There are two sides to the story. Look at the unemployment rates or recent layoffs, a 2% difference is enough to disrupt a lot of things. You don't need a lot.

AI tools has made a significant impact already. But that significant number isn't '100%'.

On the main topic, of course you can't replace a team of 8 compromised of seniors, mids, and juniors with just 2 seniors. Nowhere near that.