Ego and money.
They're still a major international club with a lot of exposure and there are only so many jobs
They also churn managers enough that if you come in with a reputation and it doesn't work out, there will be other suitors
I think it's trickier for someone like Hoeness - does Stuttgart provide the resources and ability to stay in the European spots? Is this the high water mark and the time to go? If he doesn't excel in England will be get stuck with a style that doesn't fit?
Where does someone like that go if they don't make it a year?
Seems more risk for both sides.
It's a goofy industry with managers. In Italy Thiago Motta is a hot name. I follow Genoa and they hired him late in 2019. Ownership and team structure was a mess. He was there 10 games and didn't even get a transfer window. Just tried to do his best with the mess while getting settled into managing.
Since he had some outspoken ideas on managing and setup, he was pretty much kicked and ridiculed. Davide Nicola came in and did what he does, gets a team to claw and fight their way to survival and then released before the next season. The story then was about how much of a failure Motta was - couldn't even get the team to perform like Nicola.
He was out of work for 2 years before Spezia took the risk. Worked out well enough he was able to go to Bologna. That has worked so well, he's become a sought after name and people are loving how he sets up a team.
Genoa went on to an ownership change and relegation and have now started to stabilize - although the ownership group seems to be struggling with every aspect of their business except Genoa
Someone like Marco Rose in Germany. Came up through the RB system, took over Gladbach and led then to the champions league - was basically a folk hero there. Jumped to Dortman and was dismissed quickly. Found safe landing at Leipzig and has kept them in the top 4, but never really a threat to the top. How do you define someone like that?
It's rare to see much stability for one reason or another and managers seem comfortable with that reality