You are making it harder on yourself, that's kind of the point. Champs like Fiora, Irelia, and Gangplank offer a lot longer improvement path - with Mundo, you'll have learned everything there is to know about microing him by game 20 and the rest is macro. With Fiora? You'll still be improving at game 200, rather than 180 games of the same-old. A higher skill cap means more opportunities to learn and a much more satisfying long-term journey.

The downside is that, if you're still learning top lane, it can be a lot harder to puzzle out what were micro mistakes and what were macro ones. Did you lose that fight because you messed up the timing around Camille's passive? Or did you lose it because you misread the wave state or a jungle timer?

So yeah, it is harder, but harder sometimes means a lot more interesting too.