The majority of warriors in the ancient world fought using spears and shields. These were inexpensive and had many positives. Spears had superior reach to swords, making it easy for a line of men to form a strong line.
In the ancient period, swords were mostly used by nobility as a status symbol. They were expensive to make and required a warrior to put himself in greater danger by getting close to his enemies.
In several reconstructions I have seen, men armed with spears easily defeat those armed with swords. The spear's reach allows a warrior to take control of a larger area than the sword.
In general, it takes longer to train someone in sword fighting than with a spear.
Why then were Roman legionaries armed with swords in the Imperial period?
This is more Gladius vs. the longer Spatha but there is a fair bit in this reply by u/Ambarenya about why the roman legions were benefited by a short sword. As always there's more to be said but it is of value
More can always be said on the matter, as you've seen. Of course, the "y romans use sords tho" question is reasonably popular on the sub, and here's a few previous posts for your consideration: