On the ArkType website they talk about speed and DX, but no mention of bundle size. I assume, and maybe this is an unfair assumption, that's because it's bad. I haven't come across ArkType until just now, but I was just checking out Valibot today because it's got a small bundle size.
These numbers don't reflect anything useful. This is the total size of the code in the package, most of which will be tree-shaken. In Zod's case, the package now contains three independent sub-libraries. I recommend plugging a script into bundlejs.com[0] to see bundle size numbers for a particular script
