The Higgs was discovered at the LHC. Before that there had been theories with no experimental evidence.

The point is more that we can do experiments where we expect to observe interesting things or experiments to validate existing theories. If you have an experiment to validate an existing theory, it doesn't really make sense to repeat the experiment on a much large scale unless you anticipate actually being part of the first category (new observation, no theory).

The problem with colliders is that the next energy thresholds where we expect to observe unexplained phenomena are a couple orders of magnitude greater than the proposed collider. So we could really only confirm existing theories unless something major is hiding in the energy gap. This seems unlikely.

Critics want to put the money towards avenues where we're likely to observe new things instead of confirming validated theories.

As a counterpoint, black holes were also proven rather than discovered. We have to do these sort of validation experiements, or it's not science.

What do you mean with 'new physics'?

And no, the higgs was a theory, now proven right (maybe you mean that by 'new physics'?)

Sorry but your view on the world is just depressing, its like we need 'new science' 'new physics' whatever that means, but building the experiment to proof a theory is right, is too expensive?

And no the JWST is a space telescope NOT something completely different from hubble, it's a telescope.

JWST covers different wavelengths than Hubble, which is a meaningful difference as far as telescopes go. The proposed LUVOIR or HABEX telescopes would be the successors to Hubble.

I'm not the OP, but the thing that's depressing to me is putting so many of our resources into basically a repeat of what was already done, but slightly bigger and with no expectation of finding anything significant. I mean, are we out of ideas?

23B is NOT 'many' resources, and this is why they do it:

SOURCE https://www.nature.com/articles/d41586-019-00173-2