Your claim that
when thinking about superposition, it seems physics laws will work fine with or without superposition
is pretty much completely incorrect, and there are plenty of experiments that can only be given a consistent interpretation using quantum superpositions. You can take your pick from just about all of quantum mechanics; my favourite is the experiment in the second half of this answer, but you can equally well consider Mandel dips, atomic clocks, spin echoes, every single experiment where entanglement plays a role, the structures of every atom and molecule and indeed the basis of all of chemistry, and a myriad others.
If you want a list of all the experiments that need superpositions to be explained, though, this is not the venue for it.