When you burn a bridge, you notice. Lots of other people notice, too. But before a bridge can be burned, it has to be built – so if you’re burning bridges at all, you’re actually still doing better than some people.
Some people never even build a bridge to burn, and unlike the problem of burning bridges, the problem of not building them is so subtle that no one notices – maybe not even you.
Think about how you made the friends that you have. Likely they started as circumstantial – you worked together, or you went to school together, etc. But then you liked each other enough or shared enough interests that you started spending time together voluntarily and now you’re friends! It’s a neat process, but ask yourself – why doesn’t it happen more often?
Every time someone interacts with you, in any context, they’re making judgement calls. What you write, what you say, etc. It affects how they perceive you. But they aren’t very likely to tell you unless it’s positive. If they want to become your friend, you know. If they think you’re a jerk, they probably just move on.
Now, maybe that’s on them – you won’t (and shouldn’t try to) become friends with everyone. Or business partners, or romantically involved, or what have you. But if you do want more friends, business associates, or romantic partners than you currently have, the first thing to look at is which bridges you might not be building.