On the flip side, this has a cost of creating siloing/low bus factor, so if you were to ever get in an accident that took you out, or you left the company, the company would be potentially completely screwed.
When I was a team lead, I made it part of the “definition of done” that you had to have documentation and knowledge sharing. Now, I still have both an overview of my proposed architecture before I start just to make sure I didn’t miss anything, Visio diagrams,Powerpoint slides, wiki documentation, an “architecture review”, etc. I hold myself to the same standards I held anyone on the team to.
From a career development standpoint, software developers are a dime a dozen. It’s the people who know how to communicate effectively are the ones that get ahead.