So your premise is kind of flawed. Also, Bridgeton is a work of fiction. That said, there are some things that are indicative of Regency culture and morals, so I'll try to explain them in the context of this fictional work.

The number of dukes, marquis, Earls, Viscounts, Barons, Knights is not an even triangle. There are historically very few marquis, although in the regency era it was not a pronounced as it is now. So that's why you only see a few Earls and Marquis being talked about in Bridgerton. A Viscount is considered a high rank. Now, its almost unheard of, but at the time, being "made" a baron is not THAT hard to do with enough connections/wealth/service to the crown.

Additionally the title is important, but equally is the LONGEVITY of the family line. Especially because the "age " of baron family lines might be shorter. Some country gentlemen (People with estates but no title) can be seen as having more pedigree than a newly-minted baron.

If you are a "new" baron, you are socially outranked by the families that have been around longer. Which is why while the Featherington family is an old one, they question the parentage of the "New" baron, because he was raised in America, and presumably his mother is not someone with pedigree. The question is not if he is a bastard, its about whether BOTH parents had a long pedigree.

So a winning combination has: Title, Pedigree, Reputation of Respectability, Wealth.

In Bridgerton you do see that there are several actually-titled men that everyone dismisses because of Reputation issues (open with mistresses etc). Being a "rake" is not nearly as unrespectable as you'd think at the time. it means that a man might have vices, but he generally keeps them controlled to standards where the family isn't forced to disown them. The Bridgerton boys (and Duke Hastings) all have mistresses, but they generally keep them on the down low, so it's ok ( I will not make a statement about current morals here.)

Its also why some of the men who are simply Mr. are fine mates (think of the younger bridgerton sons) even if they don't have a title. (although obviously being wealthy doesn't hurt) They might not be the best option, but the Bridgeton family is a very old and respected one so they 100% have the pedigree.

The Bridgertons obviously have wealth as well, so while the younger boys have 3/4 attributes to make them good catches, Anthony has 4/4, so all the mamas are going to be all over him.

That is nothing to say about how personally charismatic they are. (and the whole Bridgerton family is known to be so charming and well liked in society. ) We see with the very nice Mr. Finch, that obviously men and women alike were judged by their personality and looks. He's from a pedigree'd family and presumably has some amount of money, and has done nothing to damage his reputation. but he's not the most attractive or clever fellow so he's not nearly as desirable. in season one Lady Featherington makes a scene at a party (!) because her husband is making a marriage to the "perfectly acceptable" Mr. Finch hard for their daughter.

Women are judges basically on Pedigree, Reputation, Charm. While there are fortune hunters and obviously if the girl had defects in those three, wealth would be a point of interest, it was usually less important than being "of the right stock" to bear children.

Again I have simplified a lot of this, but there are TONS of etiquette books from this era that literally spell all of these rules and considerations out.