I've seen what you described as ".1x developers". It's not a big deal, usually because businesses, that hire .1x engineers, rewrite their entire products every 5 years or so. And when you start fresh from scratch, it doesn't matter if you are a 10x or a .1x: business only cares about pushing something to production as fast as possible. Technical debt will be fixed in the next batch in 5 years... by rewriting.

In more serious/long-term companies, since the interview process is more difficult, you don't usually encounter .1x engineers and what I've described doesn't happen.

All in all, there's room for everyone (.1x and 10x)