Sadly, that's the nature of circuit breakers. With fuses, simply change the fuse and it's as good as new. When a breaker trips under load, there's an arc between the contacts, which naturally leaves arc-scores on the contacts. When you reset the breaker, these scores are in the current path, creating resistance. Repeated tripping of a breaker under load can de-rate it significantly.
Using a breaker as a switch on an inductive load can do the same thing. We use the breaker as the shut-off switch for our 15HP compressor (the disconnect is outside in the compressor cage). I have a label next to that breaker that says, "Do NOT shut off while compressor is running", for that reason. Those breakers are about $300 each, and I despise changing them. I have to shut down the entire shop's three-phase power to do it.