I've heard that the idea of medieval European peasants being levied by their lieges into armies is no longer considered accurate. Is this true? What does the current scholarship say on the matter?

It's one of the many long-persistent notions about the Middle Ages that keeps circling about in the popular view despite academia having long moved past it. More can always be said on the matter, so if anyone else would like to contribute here, especially if you can cover someplace not Medieval England, please go ahead and do so! With the caution that your post may well be added to the Medieval Armies Compilation, of course.

To your questions, OP, these posts as drawn from said Medieval Armies Compilation may be of interest to you:

u/Rittermeister observes some concerns while expanding on Anglo-Norman troop composition;
u/MI13 examines the income ranges of English combatants and a notable change in recruitment method;
u/Miles_Sine_Castrum, Rittermeister, and MI13 also have a fair bit on non-noble combatants and where some categories break down (most of it is in the comments beneath the post - the whole thread is worth a read).
Rittermeister and MI13 also speak on equipment and related matters, which are relevant to your concerns.

Some more links in next post.