[yellowapple]

> Maybe you can repressurize the tubes ... assuming there is power to do so

Fail-open air valves are a thing.

> to evacuate people

Emergency exits are a thing.

> If a window breaks

Why would a shuttle in an underground vacuum tube have windows?

> The main problem and you can't engineer around it

Pretty sure people said the same thing about most of the modes of transportation I mentioned above.