I have the same issue with every MOBA out there.. not having the ability to increase the font size, at least to some extent. i'm on a 1366 x 768 resolution and the UI size is maxed out and the text is way too small for what i'm personally comfortable with, and i'm sure other people have the same issue.
I shouldn't have to lower my res just for better readability and comfort, nor have to increase the UI size significantly again just to be able to read the text without having to practically strain my vision. especially for example, the stats box, like what the heck is that size 8 font? i'm perfectly fine with the resolution and the UI size, the font size is the issue, plain and simple
just simply having the option available of 'small/medium/large/extra large' font size would help massively.