Hmmm.
Why the lack of monorails? Because of lobbying. Not because of engineering or superiority. Monorail IS cheaper and superior to any of the twin rail systems. The real issue is that twin rails were established in nearly all nations over 100 years ago. So, it is hard for Monorail to gain traction, esp when there are multiple designs.
Now as to hyperloop, it really has the only design that can make it cheap to build and safe.
You say that it is not safe, when the exact opposite is true. They are looking at electrical storage on-board. That enables the air compressors work, just like they do for jets. IOW, a pressurized container is no big deal because we have been doing this for over 60 years (all aircrafts that fly at 15K and higher).
It should be easy enough to either provide side-outs, OR even better would be to provide for 3 tunnels in which the 3rd can be used for bi-directional traffic (i.e. when traffic is much heavier in one direction, then use 2 tubes) or as a back-up. If a car develops an issue, then it is possible to stop 1 tube and re-pressurize it. With the 3rd tube, it is either not being used, it is already going in the same direction, or it is being used in opposite direction. If it is the later, then you have to wait for that tube to clear out before using it for the new direction. And if this moves at 700 miles / hour, and there is 'stations' every say 70 miles (i.e. 10 minutes), then issue solved.
Plenty of issues to solve, but I think that hyperloop really is a smart way to go.