They get government funding for both (British resident) students and research so the government has leverage but would have to use that to incentivise them. I imagine at least some other European countries are much the same.
An even trickier question if you are interested in digital sovereignty is how to get the private sector to do the same. Running everything on AWS and requiring a mobile app to do anything seems to be almost instinctive for many organisations.
Now I do m365 consulting and some Azure and I feel terrible. First of all those are terrible products, they lock you in heavily, they are overly complex. I would love if we started selling sovereign cloud solutions, open desk etc and I think our customers would be interested too. But we don't.
I'm actually thinking about starting my own business.