That's exactly how it works. Every input of AI performance improves over time, and so do the outcomes.
Can you damage existing capabilities by overly specializing an AI in something? Yes. Would you expect that damage to stick around forever? No.
OpenAI damaged o3's truthfulness by frying it with too much careless RL. But Anthropic's Opus 4 proves that you can get similar task performance gains without sacrificing truthfulness. And then OpenAI comes back swinging with an algorithmic approach to train their AIs for better truthfulness specifically.