Snapchat has to be the all time worst offender to me about abusive level of notifications. Luckily, you can turn them off, but holy cow batman, that's a lot of notification options to deal with.
Remember when Android used to let notification senders hijack turning your screen on, Snapchat used that one a lot.
For me the worst is NextDoor. I don’t have the app installed, but they also have email notifications. There are seemingly 100 options and I turned them all off when I first made the account. Periodically they add new ones and auto-enable them for everyone. There is not universal way to shut them off, short of blocking them all together or deleting my account. The account was such a pain to setup that I’m hesitant to delete it, for the 1 time every couple years where it’s useful.