lol even the argument that batteries are "built in" has never made any sense. You can tell some have never built a PC before, if you can change out a fucking case fan, you can change you a battery from PS3, PS4, PS5...
I've only had to change a PS3 one and that was by choice as I saw it was getting lessor charge and it was a MGS4 theme PS3 controller from a PS3 bundle, ordered the battery for like 10 bucks, replaced it in mere minutes, have had it working for years (will likely last much longer as I don't game on PS3 as much now days)
so I'd rather pay the 10 bucks and have years of not thinking about vs this weird AA battery thing lol
I haven't had to do anything with my PS4 controller as I got one of those PS1 edition ones, that was like 7 years ago and the change is still normal...so maybe next year or the year after or something I'll change out the battery, but I'll take that trade off vs some AA battery thing all the time lol