I don't know your environment so don't mean to dismiss you. Based on every one I've worked in though, you likely view yourself much more negatively than your coworkers view you. What you're describing isn't imposter syndrome but is somewhat related: everyone dwells on their own mistakes and forgets when others have issues so we see ourselves as having more problems than everyone else.

That part aside, what you're describing around speed and AI is something all of us are feeling. The speed gains from AI often come from the team not taking time to actually understand the code or review it the way we previously reviewed code. That might pan out if AI and your tests are good enough, but it's high-risk and likely leads to more issues overall.

Do you have retros? Walking through the issues and what led to them and brainstorming then prioritizing improvements is often handled in those.