Getting into management is definitely more of a hours thing. But manager productivity is different; it's about talking to lots of people and not maintaining focus on one thing for hours. It's a shit-load easier to do from anywhere. But at the same time, it's definitely time-intensive. When I was CEO of a 200+ organisation I worked 10+ hours a day. The hours were a lot easier, though. Less hard thinking and focused concentration, more half-hour meetings which seemed to be mostly about listening to other people tell me why they decided to do something.
I was in Germany for COVID - I can see why you say this. But that's still only true if you stay in large organisations. In smaller orgs you get more flexibility, even in Germany. You can still become an expert developer and get the decent money without getting into management. Having said that, it is easier to climb the salary ladder if you get into management. But you can never go back; it's very hard to get back into a developer role if you've been a manager. Beware of what you wish for.