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.

I will constantly take parts from modules, but I've never run a module verbatim; not an old module and not a new module.

In my experience, it seems like (from what I've seen on the web, so there's possibly a bit of sampling bias there) that homebrew is somewhat more common, but it's definitely a mix. Personally, my way of doing things is to take old modules and take bits and pieces from them as inspiration.

I use them more as a general outline or idea. The Mystara Adventure Crown of Ancient Glory is a good one to mess with as is Queen of the Demonweb pit for AD&D. The older the module the more it is just guidelines. Palace of the Vampire Princess is a great one that the GM/DM will have to do a lot of work on.

I’ve tried running some of the older modules, but they lack the streamlined playability that seems to be a large part of the OSR scene. Keep on the Borderlands, while seminal and deeply influential, doesn’t have a great layout. It’s writing is in big block columns of text that make it challenging to find the information you want when you’re at the table. I tend to like reading through the older adventures for inspiration more than to run them. I find myself gravitating towards newer gonzo adventures like the stuff in DCC.