I ditched my entire foster family when I was 18, 25 now and never felt better. Bunch of Sociopaths the lot of them.

If they are just greedy selfish ignorant twats then yeah I don't see any harm in getting rid of toxic relationships. But the fact they were at yours says they do care to a degree, but is that cause they care about what would be left to them?

As long as you have some kind of friendships and you aren't on your own all the time then you're alright but if you are then that's not gonna help you sitting being jealous of everyone elses family support and not talking to anyone. That'll just leave you open to mental health problems. At an old age you need to be social to keep yourself going, make friends like yourself and such.

Good luck and all the best.