I’ve never actually run any of the old modules like Keep on the Borderlands or anything like that. I’m much more used to homebrewing a setting entirely or at most grabbing a few elements from a published adventure (I took a bunch from Willow, for example). I think this is why most of my favorite systems tend to be more in the NSR camp; I just never end up needing compatibility with older material.
Is running retro adventures in their entirety the most common practice for OSR tables? Or is the homebrew approach how most people are doing it?
Like you, I run almost entirely homebrew content. However, I hear from numerous folks that run adventure modules, both old and new, at their tables. I’d guess there’s probably a good mix of both styles in the community at large, not to mention the folks who like to take modules and then rip them apart and mash them back together to form something new.