For me it’s Whatsapp. Like 99% of people i know use it so yeh… i still need it. I am considering moving the Whatsapp Gdrive backup to a local backup btw.
Google photos is also a major problem for us. We have a lot of stuff that want to migrate to different service (or store locally).
iirc theres a strict account settings in whatsapp. It literally blocks random messages, invites from groups and individuals. For groups, you cannot be invited or mentioned. For random person, he or she needs can only contact fully until you accept their request.
Not advocating for whatsapp, its owned by a shady company lmao, but these features are pretty ok.