Are they going towards retention bonuses for the best teachers (i.e., the ones whose students are performing above the mean on standardized tests)? That's a great thing. Are they going towards adding to bloated administrations that don't have a quantifiable benefit to the students? Not good.
And as you point out, these additional funds are often just spent on excess stuff, i.e., "we'd better use it or we won't get it all next year." My children's school system does a great job with their budget, but when we flooded schools with "pandemic" funding, there was so much left over that we didn't need that they just applied it towards the cafeteria funds and gave school lunch for free. That was certainly nice, but it's the sort of thing that's not entirely necessary for the majority of families, and added up over the thousands of school districts across the country, we'd be better off just applying it against the national debt.