I think you're missing the point the comic is going for.

Fundamentally, mathematics is built off axioms. An axiom is an incredibly simple statement that presumably true within the system they define, such as "the quantity one exists" or "the operation addition exists", then uses these axioms to build mathematical proofs starting from them to draw further logical conclusions, such as 1 + 1 = 2.

If you continue following these axioms to their logical conclusions, and use those conclusions to follow to even further logical conclusions, you essentially end up with the entire field of mathematics.

Then if you take those mathematical conclusions and apply them to the physical world, you end up with the entire field of physics.

Then if you take the entire field of physics and apply it to molecular interactions, you end up with chemistry, and if you take all of chemistry and apply it to biological organisms, you end up with all of biology.

I'm not trying to say you're wrong about people arguing in bad faith or with not enough evidence to make their untrue claims. But this is just a web comic. It's just making a joke that if we trace everything we know back through all our fields of studies, we end up with the incredibly simple origin points of mathematics.

It's funny.

Laugh.