I've had very limited interaction with this guy's work but I can't quite see what contention he has. I get the very funny meme where pi doesn't exist but on a serious note all he seems to do is point out unintuitive but obviously true statements in mathematics like a shape being an infinite collection of cross sections and then acting smugly about it, as if that somehow makes it nonrigorous, for example he says "would a mathematician also look at a tomato and see an infinite number of tomatopoints lmfao look at how weird this sounds!" All while positing nothing beyond sensationalist value. I read one of his "papers" and he asks his argument around things that are just plain wrong, for example that all sets are infinitely recursively defined, i.e a={a1,a2...} whereas a1={a11,a12...} and so on when you could see even in an introductory book like enderton that all finite sets terminate at an arbitrary point into sets of sets of sets... of empty sets.
Seems he has a very hard time with abstraction while not having any paradox/inconsistency to show for this and supplements this weakness with appeal to authority or sensationalism as described above. An example of this that I saw in one of his papers is that sufficiently large numbers "don't exist" (there's a very serious problem with "existence" being effectively meaningless mathematically but I'll leave that for another time) because the universe would end before a computer could calculate this number, in fact he sprinkles in some diverting humour like "well after you've killed every last person to fuel your calculation you still wouldn't be close to finding this number", does he not know that mathematics is independent of time and that larger numbers don't start "existing" when more powerful computers do? This is honestly baffling, I'm thinking this guy's a complete charlatan.