And when you're in an existing company, stuck in thing X, knowing that it's obsolete, and the people doing the latest Y that's hot in the job market are in another department and jealously guard access to Y projects?
How about when you go to interview, and you not ONLY have to know Y, but the Leetcode from 15 years ago?
So maybe I've given you another alternative to 'it has to be power, there's no other rational reason to go into management'.
Here's a gentler one: if you want to build big things, involving many people, you need to be in management.
Do you enjoy brick laying and calculating angles around doorways? You're the engineer. Do you want to be the architect hiring engineers, working with project managers, and assessing the budget while worrying about approvals? They're different types of work, and it's not about 'power' like you are suggesting. Autonomy and decision-making power are more the 'power' engineers often don't get (unless they are lucky, very very smart or in a small startup-like environment).