The "specific program" I have trouble with is Autodesk Fusion (formerly Fusion 360). There are projects that try to run it through Wine, but there's a specific function that isn't implemented in Wine right now that Fusion relies on as part of its authentication service, so it won't log you in correctly, at least on the default Mint install. I think at least one of the relevant functions is currently in the Wine beta, so it may work again in a bit--I did manage to get it working briefly at one point, but I somehow screwed it up again subsequently. (I may just have forgotten how I launched it...I think I have two versions installed at this point, the Flatpak and the Snap install.) But even when it worked it was slow and janky in a much more severe way than when it runs natively on Windows.

The "specific program" my dad is interested in is Hesuvi, a piece of headphone virtualization software that also does equalization and crossover. At some point I identified a program I though would work on Linux as an alternative, but I would want to test that before committing to switching his computer over from Windows, and I haven't got around to that yet. Other than that he mostly uses Zoom, and I think I tested that and it worked okay in Mint, though my memory is a little weak on that too.

I dunno. Basically everyone has their own little patterns they use with their computers, and switching to Linux requires changes to those patterns. It's an adaptation. That's not to say it's not worth it--for a ton of people it probably is. But I'm not sure my aging parents can do it, and thanks to Fusion, I'm not sure I can do it either, because I just don't have a good replacement.

The other option I'm looking into is Windows IoT LTSC. That omits a LOT of the problematic bullshit.

I'll figure something out before the end of support, anyway.