You mean your core tech skills will be suspect if you aren't a decent project manager? Well that's a depressing thought. Though in my experience so far we have dedicated project managers. But maybe you are right.

I think dedicated project managers are a good idea to keep people focused, but I also think if you've been buildings things for 20 years you should have absorbed enough of the process to be at least basically capable at it. That's not really true of people management (an entirely different skillset) or technical writing (though it's a bit closer) or even product management (but if you code mostly customer-facing features, probably you should have picked up a lot of this too).

If you've just been a "turn the crank" developer implementing someone else's sprint-scoped tickets for 20 years, you probably topped out after around five years. (Or you're doing all the interesting stuff outside work, in which case... you definitely have project management skills.)

completely agree but I think it's more general than that.

A strong senior should be able to do any of the roles all the way up and down the chain, including "product manager", "business analyst", etc. It's an issue of time and scope rather than skill.

note: I'm aware that most business analysts are domain experts, my point there is that a senior can both analyze a problem and create a solution and can interface with domain experts where needed.

Interesting about the tech writing too. I'm not good at this. I've seen this mentioned on hacker news

https://www.amazon.com/Docs-Developers-Engineers-Technical-W...

I'm think I could do with reading that. As could the team I'm on.