Question

how does friction help with writing?

Answer 1

It's more of a contact force with opposing nature. Thus it tends to hold the irregularities in the surface and helps the body to slide over or drag without slipping.

Answer 2

friction is the opposing force between two surfaces.
writing is only possible because of friction otherwise the instrument we are using will be slippery. as if you can put some oil on your notebook pages and then try to write on that , it wouldn't be that easy to write as earlier.