Illustrator allows us to set ridges per segment when applying a live Zig Zag effect.
Cool, we can use it creatively... sometimes... in very rare occasions...

But most of times we need the frequency to be uniform for the whole path, like Roughen does.
We can’t use a brush to do it really, and we can’t make Ai to re-divide a path into segments of equal length (a cool request on its own, but it won’t solve the problem anyway... but I ahve to mention the PathScribe plugin allows this).

There is this cool Random Zig Zag script that that does this and more as a filter (https://www.youtube.com/watch?v=FHEAk6s9NcE — definitely worth buying), but it’d be great to just have it from the box as an option for the effect.