When you’re younger a friendship ending feels like “I failed because they dislike me, so no matter how I actually feel or what has happened, if just apologise enough, or be accommodating enough, I can fix it.” That can lead to tolerating an CRAZY amount simply to avoid the psychological horror of someone walking away from you.
Adulthood teaches you something way more useful: you WILL lose people along the way. Good people. Normal people. Sometimes you just don’t get on. That’s fine.