We don't know, but why is that question even relevant? The vaccine produces a robust protection that natural immunity has not proven to. Whether vaccine + covid vs vaccine alone is better is irrelevant to whether we should be mandating the vaccine.
I agree that everyone should get the vaccine (duh!) I got it myself last December and got my wife and kids vaccinated very early, also. But that's very different from the scientific question of whether pure vaccine based immunity is superior to natural immunity. You can't say that, or even compare the two without knowing how many vaccinated also have naturally immunity. That's all I'm saying. In no way am I saying, "Don't get vaccinated." Everyone should get vaccinated!
Because here's the real truth, that nobody is saying:
Vaccine immunity isn't strongest. Natural immunity isn't strongest.
Having both is!
And that's what most of us vaccinated, have. We've been vaccinated and our immunity is robust. It's because we've been vaccinated and we're living life coming in contact with the virus.
More reason to get vaccinated.
But saying, "I'm right because the experts are on my side," without even saying which expert you're quoting or showing their proof means nothing. Plus, experts are wrong often. They produce bullcrap, junk research (not always but( often and are proven wrong (not always but) often when study, after study after studies come out, with disagreeing findings. So we need to listen to them, but still use our own brains.
And yes, get vaccinated (duh).