Android 15/16 does allow you to control notifications even lower, at the level of notification category, but indeed the app must have chosen to use them.
OEMs like Samsung turn off that ability by default unless you toggle it in "advanced settings". Thank you Samsung!
Yeah the problem is a lot of apps dump their ads in the wrong category if they even use categories :(
Most apps that are in need of notification control either:
a) bundle everything in one category, from critical notifications without which the app can't fulfill its purpose to "HEY YOU HAVEN'T USED ME IN A DAY, USE ME NOW" spam
b) create a new category for spam every time they feel enough users have turned off the previous one, which is often