[Johnny555]

the only thing it has done is confirm what we already knew decades ago

I thought it confirmed what we thought we knew (and is the only way to confirm it), so that doesn't seem like wasted money.

[GrumpyYoungMan]

It would be more precise to say that it didn't show us anything we didn't already know (other than the Higgs). There are various indications that the Standard Model is not the whole story but the LHC gave no hints whatsoever on what directions to explore next. In that sense, it was wasted money.