Why do cat hairs tend to stick to our clothes more than those of dogs or other pets?

Cats have three different types of hair: guard hairs within the outer coat; awn hairs (intermediate-sized hairs forming part of the primary coat); and secondary hairs (downy hair found in the undercoat).

The gaurd hairs are slender and have microscopically small barbs that are very rough. This is the main reason cat hairs stick to clothing.

https://en.wikipedia.org/wiki/Cat_coat_genetics