Oh yes. People often point to the fact that slavery in the ancient world wasn’t race-based in the way its modern version became based on race, as if that somehow magically makes slavery not slavery, but the truth of the matter is that slavery in the ancient world was just as brutal and dehumanizing as its modern counterpart.

In the particular case of ancient Rome, this plays out on a number of levels, from the legal on down. Enslaved people in ancient Rome had no legal standing as people. At all. Slaves had the same legal standing in Rome as things. Watson notes that while the Twelve Tables gives the penalty at injuring a slave as half that of a free man, treating slaves in a legal sense as inferior but still as people, but that the 287 BCE lex Aquilia gives the same penalty for the injury of slaves as the penalty for the injury of herd animals. Slaves could not initiate legal action on their own behalf if they were injured or assaulted. That was the right of the person who owned them, and any penalty which resulted from that suit went to them.

And that’s if a slave was assaulted by someone who did not own them. If slaves were legally vulnerable in the outside world, that’s independent of the physical abuse they suffered in their everyday world. There were some jobs that were known to be particularly terrible: the mill is the typical threat for slaves in comedy, although it was hardly the only job with such a reputation. One of the most common ways in reports from antiquity, from Egyptian documentary papyri to 2nd century BCE Roman New Comedy to Apuleius’ 2nd century CE Metamorphoses, to identify slaves and freed slaves was through the scars and physical disfigurement suffered in slavery. In the play Amphitruo, the character of the slave Sosia, when faced with his double, the god Mercury, dressed up as Sosia and claiming to be Sosia, remarks that:

By Pollux, certainly when I consider that man I do recognize my own form,

just how I am - I’ve often seen it in the mirror - it’s too similar to me;

Just so, he has a traveling cap and my clothing: he’s as like myself as I am;

calf, foot, stature, hair, eyes, nose, or lips,

cheeks, chin, beard, or neck: all of him. What do I need words for?

If his back is covered in scars, nothing is more similar than this similarity. (Pl. Am. 441-446)

Sosia’s tergum cicatricosum is the thing, out of all the features Mercury steals from him, that could convince him that he’s looking at his own image. Scars physically marked out slaves and, even if they were freed, followed former slaves. In one of his epigrams on an edict by Domitian reviving the lex Roscia and re-regulating theater seating, Martial points out a former slave trying to pass as an equestrian (even freed slaves with the equestrian census were barred from the equestrian order) by covering over the FUG branded into his forehead - fug was a shortening of fugitivus and was used to mark runaway slaves (Mart. Ep. 2.29).

There are a number of ways one could come to be a slave in ancient Rome, including being born a slave. In the imperial period in Rome, this was the most reason for someone’s enslavement, but that isn’t the case for every point in Roman history. In the 3rd and 2nd centuries BCE, enslavement through capture in warfare was incredibly common, although both birth into slavery and enslavement through warfare were not uncommon in either period.

But no matter how you came to be a slave, slavery constituted a complete and total loss of personhood. Whether a person was born a slave or enslaved later, their name was given to them by the person who owned them, stripping away the name they were born with. It’s what makes Sosia’s joke in his confrontation with Mercury that, since Mercury has beaten up four people already that night, he is afraid he “will change [his] name and will become Quintus instead of Sosia” (Am. 305), Quintus meaning both “the fifth” and the aristocratic Roman praenomen to which Sosia, as a slave, had no legal right, so interesting. Sosia, who calls himself a verna, a born slave, and whom Mercury contrasts with himself as someone who was put into slavery (something a family’s paterfamilias had the legal right to do), is claiming a Roman name and identity. Related to this, slaves had no legal claim even to family or ancestry - something that is very frequently celebrated by freedmen after manumission - effectively removing their ties and relationships to other people on the legal level.

This is just a start. A few by no means exhaustive places to begin for Roman slavery:

Watson, Alan. Roman Slave Law. Baltimore: John Hopkins University Press, 1987.

Bradley, K.R. Slaves and Masters in the Roman Empire: A Study in Social Control. New York, 1987.

Harper, Kyle. Slavery in the Late Roman World, AD 275-425. Cambridge University Press, 2011.

Joshel, Sandra R. Slavery in the Roman World. Cambridge University Press, 2010.

I count it as a major historical pet peeve.

In terms of some numbers and descriptions for at least a period of Roman slavery I recommend reading Carthage Must be Destroyed. The descriptions of scale and intensity for Roman mining in Spain in part answer your question. Hundreds of thousands of slaves just working mines in Spain, on a scale not seen until the industrial revolution in that part of Europe. Smog that birds would fly into and die, this all on the back of slave labour. I don't have the book on me right now but the lifespan was 8-12 years for a mining slave. Being a mining slave at least during this time was a death sentence. They were not part of their owners family or regularly buying their freedom. Galley slaves and in particular farming slaves on large estates are also going to often have horrible experiences. A description of farming slaves in the book sound eerily similar to a plantation slave. There is also going to be rape of slaves happening in most/many cases of slavery and certainly was present in ancient slavery.

The slaves you are hearing about are urban slaves, and even then it wasn't the standard to be treated like you describe. It's would be misleading to have a positive image of this kind even if high skill or value slaves would be more likely to get treated better. Famously you had Greek slaves who would be bought to teach.

There is a complex politics to slave history, and comparisons are used to diminish or exaggerate depending on the ideology of who is speaking. I'm more fmiliar with Carribean and Roman slavery than any other but both need to be read with some care. American slave owners would exaggerate how bad slave owners to the south were to make themselves look benevolent and civilized in comparison. At the same time the profit margins, refinment process of sugar, and presence of mines did mean that slavery in Brazil and the Carribean could be significantly "worse" by some measures. Then those measures are complex because you can't just look at something like birth/death rate because the same factors affected gender ratio. You then have people who want to hold American slavery accountable and are biased. You have a Christian element who want to soften biblical slavery, or exaggerate pagan slavery. You have the popularity of Rome and Greece being a factor in diminishing theirs. Not to mention these factors are constantly changing.

Regardless the answer to your question is simple and it is absolutely the case that slavery was brutal prior to European colonialism. Modern chattle slavery is different and I think it heathly to find the racial components particularly disturbing but that should not become a motivation for what I find essentially to be slavery apologetics of another kind.