Because whether you like it or not, social media is the easy-track to connect with people of all varying degrees and connect through common interests and even ideals. It's a lot easier than in the 2000s and 1990s when all you've had was an e-mail and probably chat room hopping. You just had to know someone else's e-mail like you would have to know someone's number to call them, that's how it worked.
With social media, you can just breeze through friend lists and comb over searches to find friends and everything far easier. It's easier to connect with people that way than ever before. And losing out on that, can sting.
I sometimes wished it wasn't that way, but the people have largely decided we needed something more than just writing e-mails to eachother.
As far as I know, they use things called Evercookies and it's been a thing now too. If you have an Evercookie, then it won't really matter what browser you use or even if you clean the cache and history. You have to deep scrub your system and practically all traces of your browser to even get rid of those.
And even so, basic networking is a no brainer when they can just flag your IP and it won't even matter how many times you've done that process.
VPN and Incognito browsing is the way.