I typed out a long rant, but decided to delete it. It's not really the place, and it's not like it matters what I think. I'd get some likes, some replies from people who will say "well, actually, you're completely wrong", and for what?
Anyways, I think at this point I think I have my answers. Bonus actions are intended to be things you can only do once per turn, even if the majority of them aren't really broken if you could do them twice. Somehow this is different from actions, which the game is perfectly happy to expand or even allow you to take multiple ones, in a limited fashion.
Some bonus actions could be converted to actions, but the DM/GM can't commit to allowing universal conversion (or attaching a cost to them, ala ToV's Improviser Talent*).
This sort of thing was mostly fine in 2014, but 2024 has decided to improve the power of some Bonus Actions, and will likely continue to do so.
*So far, I've only found one "kinda sorta" neat thing you can do with Improviser in ToV, with the Kraken Barbarian subclass, but it loses it's luster quickly, and getting that Talent is a bit hard for a Barbarian to accomplish.
Anyways, thank you for the replies.