We waste plenty from natural gas extraction too. Most helium comes from natural gas extraction, but not all natural gas extraction facilities capture the helium, instead just leaking it to the atmosphere, where it is extremely difficult to extract due to the very low concentration. It also tends to go toward the upper layers of the atmosphere, and can eventually escape into space.

I read something on this that said balloons and helium isn't the problem, really, because the helium used for balloons is not anywhere near "pure" enough for things like MRIs, etc. Like it's a byproduct of making the super pure stuff. It's not taking away the supply, but there is less to be found to begin with.

we do not waste liquid helium on balloons. Getting helium into liquid form is not trivial.