There is a provably fair one, but in order to understand this, you need higher education than basic. That's the problem- it's impossible to prove anything to a person who can't understand the proof. Therefore, sometimes a simple hash verification is issued as proof, well, that is, the proof boils down to "look, here are 5 and this is also 5." But where did this 5 come from initially remains outside the scope (why not 8?).
Such methods are somewhat populist, since they do not strictly prove anything, except that the original hash did not change during the spin. Therefore, for most gamblers, the most important criterion is still the reputation of the casino, and not mathematical proofs that are difficult to understand.
I think it doesn't require everyone to understand the entire process behind proving the "provably fair" claim. If a few guys, who do indeed have the knowledge, go and investigate whether that proof is true or not for a casino, I think the community as a whole still has a lot of benefit from that. Now to be fully accurate, you are of course right that this is still not 100% insurance for everyone, but I think a good start if a casino passes that test from time to time conducted by random knowledgeable users.
The problem is that I think casinos hardly get tested for this on a regular basis. Which leads me to the idea that tests of that provably fair claim could as well be a community funded effort.
What I wondered about is if you run that experiment with let's say $0.10 and it is provably fair, is it still the same with $1 per spin? I ask this question because in some casinos I had this strange feeling that lower stakes seemed to be closer to the advertised rates. Could be totally subjective and wrong, but maybe someone else had that same feeling too.