Hey, OP here. I agree.

If you get a list of all the startups that got acquired or IPO in the last 10 years, you will find it's extremely rare the technical co-founder is still around. The staying rate for CEO is like 99% while the staying rate for CTO is more like 50% (making up numbers here but this is directionally right).

With enough scale, a great CTO can be hired for the right salary. The way I answer this for myself is two-fold:

1. I've vowed I will never be the second chair guy because I don't wanna get pushed out.

2. It's important to up-skill yourself so you can contribute more value than a glorified engineering manager by driving vision, being a headhunter of superstar engineers, among others high-value skills