Lemmy is more like a large forum or series of forms. Most people are in communities because of common interest whereas social media is more like looking at people around you or whom you're friends with. It's also anonymous where SM is people standing on their little soap boxes subconsciously screaming, "look at me!".
I'm not saying map replacements are phenomenal. But CoMaps is using Open Street Maps, and for my measly little area I contribute a lot of data because POI are lacking. But for most use cases, its perfectly capable.
While yes, most/all banks require a phone number to login, they can't force you to use the app. My banks require phone numbers for the text verification. Better than nothing but still shitty MFA. So I login through the browser, not app, and I have a VoIP # for text verification codes to go to. Also, the browser UI is close enough to the mobile app it's easy enough.