In KDE Connect you already need to use the modern API to pick a location for file browsing and it works fine. I picked the entire virtual storage area and that's what's available through remote browsing, but I could've picked a single directory. If all apps supported this, we'd be a lot better off.
Of course, there's a perverse incentive to put off the transition as long as possible so that stalking libraries can make more money. I think Google is moving very closely to forcing the new API with the release of Android 12, which would mean that most app developers can't really put off updating much longer.