[ndngmfksk]

If such tabletop experiments were possible, then surely the particle physicists who use these colliders would be building them? As far as I can see, they're requesting colliders because to the best of their knowledge, colliders are necessary.

A muon collider would be revolutionary in the sense that it would open up a new energy range for lepton collisions. It would also be a technological marvel.

[EvgeniyZh]

It's not that simple. There are many smaller scale experiments in HEP, all kind of dark matter detectors among them. Colliders are irreplaceable in a sense that we do not know how to get higher energies without them, but it's unclear for me that just getting higher energies is enough.

Energy scales for new physics can be enormous for all we know, I do not see any reason to expect that new physics hides "around the corner" (in a 1.5 orders of magnitude FCC or muon collider could give us). Muon collider is at least looking in a different place, and it's definitely more interesting than FCC for me, but I'm still not 100% sure it is the right thing to do, given the limited resources.

[naasking]

Those colliders need more research, but are possible (like wakefield accelerators). The physicists who want these colliders probably aren't interested in this kind of research though, so they push for classic collider designs they already know how to build.

I agree that muon colliders are a better investment than something like the Future Circular Collider though, it's an area that hasn't been as thoroughly explored.