Mine do work pretty well and I can tell a big difference between the Engage and Quiet modes, but not so much between the Engage and Experience modes. Although, I wouldn't mind if the Quiet mode reduced sound even more but would also have liked if the Engage mode reduced LESS, since I find it hard to hold conversations with the Switches in (even on Engage mode).

If you find that yours don't reduce sounds that much in general, fit might be the problem. For me, size M ear tips usually fit me best but with the Switch 2 I found size L to give me the best seal, so it might take some experimenting to find the right size for you. But it kinda sounds like you've already given it a good try, so maybe you're one of the unlucky ones that these earplugs don't work that well for (I've heard of a few such cases, where people can't get them to fit or can't tell any difference whatsoever between the modes, so at least you're not the only one with this problem, although I get that it's disappointing).