Trying to be a better person is good, but trying too hard can backfire.
Take this purely hypothetical example: someone wants to be more independent and less burdensome to others. Up to a point, this makes them less intrusive and more respectful. Taken too far, this makes them dismissive and isolated. They could miss out on great relationships by thinking “I’d just be a burden to them” when that’s not the case at all.
Again, purely hypothetical.
Sometimes trying harder to be someone better is worse than trying harder to be yourself.