It's easy for a top driver to go to the 'clearly best' team.
I have more respect for drivers who make an effort to 'build' a team. Schumacher was central to Ferrari becoming Ferrari again. It's possible that Todt could have rebuilt the team into a powerhouse without Schumacher, but honestly, I feel that Ferrari might've given up on F1 if they hadn't succeeded, and I don't know if they'd have succeeded without him.
Villeneuve going to BAR was also admirable. Maybe Williams would come back, maybe they wouldn't. Building a new team from scratch might've 'wasted' his best years, but his legacy is the Mercedes team that won a ton of championships, so a great contribution to F1.
Even Hamilton, going to Mercedes was a risk. He wasn't looking to build something though, he could see that Mercedes was on the verge of something, just as McLaren was on the verge of collapse. I think he just knew things that we fans didn't.
Verstappen talks about wanting challenges, what's a bigger challenge than turning an F1 team from literally nothing into a championship winner?
Why move to a successful Audi/Cadillac/Whatever? If Max wants a challenge, buy into Alpine. Become a driver/owner and set some real F1 history. (Or maybe finally force Red Bull to divest of Racing Bulls. If the Verstappens want to run a team so badly, why not give them a team to run?)