[quicklime]

This is probably above your paygrade, and definitely outside of your role as an IC.

In this case, I'd suggest accepting that it's just your job as a relatively senior engineer to coach more junior people, even if it's the wrong thing for the company and its customers in the long term. And in this case, it's just your job to decompose work in extremely fine detail. But make sure you're rewarded for it.

It's your manager's job to decide whether this effort is worth it, or whether to cut the other person loose.

Talk about this stuff in your performance review and in 1:1s with your manager. Don't be a dick about it, and don't put others down. But talk about how you lead the team, how you do a lot of design work and work breakdowns. And how you also write a lot of code.

If you don't get rewarded for it, be open about that. Ask for the space to focus on technical work. And if that still doesn't work, find another job.

The people who are "transverse" are a bit trickier to deal with. If you're in a large enough company, you might have the ability to move around a bit (but it might require a bit of agitating). It's not easy, but try to position yourself away from these "experienced PMs".