He is a sort of strong finitist [0]. Roughly, this means that many usual mathematical objects that rely on notions of infinity, e.g., irrational numbers, do not exist.

I came across his YouTube channel [1] years ago as a undergrad and became really confused about some ideas in logic as a result.

[0] https://en.wikipedia.org/wiki/Ultrafinitism

[1] https://www.youtube.com/@njwildberger/playlists