Facebook is moderately useful for keeping in touch with people you want to hear from and who just won't use email/Mastadon or whatever, and for interest-based groups and events. That is all. And as long as you strictly restrict yourself to using only the website through a browser and eschew their apps and carefully go over the privacy settings and tune them to your needs you should be okay. As for endlessly scrolling the newsfeed all day, well that is not so much Facebook's fault as that people who do that are probably having too much idle time and not knowing how to do some productive or more creative activity. If Facebook did not exist those people would trawl through Twitter or Youtube or something else.