I got off Facebook 1.5 years ago as well. Removed my special Facebook browser I used (removed the app long ago) and at first it was weird as I was used to hitting it, whenever I had a few minutes of nothing. But after a week or so it felt great. Less screen time, less mental burden from seeing "stupid" posts, less useless discussions, ...
Couldn't get of WhatsApp, yet, as it's too often the default for friends and family.
I lived in a foreign country recently and Facebook groups were far and away the most important tool I had for meeting people and establishing myself. WhatsApp was the dominate form of communicating with people who lived there. And Instagram was the primary way I kept in touch with my closest friends on other continents.
These things are useful, and just because they can be misused does not make them any less useful.
No doubts that there are uses. Travelling Indonesia WhatsApp was a must (due to free basics / internet.org they were most reliable communication with local Services) and now in Corona lockdowns many shops here in Germany don't update their website, but Facebook with current opening times and offers.
However I spent way too much time on it and Facebook is way to hungry for personal data.
Couldn't get of WhatsApp, yet, as it's too often the default for friends and family.