I haven't been following him, but he is someone I'm a little familiar with.

So far, I agree that it's hard to disentangle the possible causes. The case that gives me the most pause in attributing it to the vaccines entirely is Sweden. They had very high vaccination rates, but no lockdowns, and had relatively low excess mortality.

On the other hand, there are many regression discontinuity type analyses of American data that point towards vaccines over lockdowns.

Eventually, researchers will be able to take advantage of all the differences in timing of the possible causes to work it out. However, this kind of politically charged research can be difficult to pursue honestly.