In medieval ages, how much was peasent levies actually used and how important was they for the armies at the time?
For one, the Popular Knowledge picture of the 'peasant mob with pointy sticks' is definitely Not A Thing. On the other hand, depending on how you define 'peasant', 'levy', and 'peasant levy', we might come up with a "maybe?".
So here's a few posts from my Medieval Armies Compilation that all deal with what I think we can agree look reasonably close enough to peasant levies. Starting from a personal favourite, a trio of posts from u/Goiyon: