Cost aside, what worries me is your every thought (or an approximation) will end up written down forever in some database tied to your identity. I don't mean absolutely every single human being on the planet earth will use AI to be competitive, but I do think it will be to such a high degree that it will feel like everyone is using AI to stay competitive.

I'd say, "virtually everyone". For some time I'm sure you can keep up, but over time, let's say 10 years for example, I do believe people who never use LLMs will be on a way worse competitive position than the people who use AI. Prob way earlier than 10 years tbh