For me, it's hardware support, i.e my laptops fingerprint sensor just isn't supported, for the speakers to work I had to find a script that remapped the speakers, multiple desktops (especially with different resolutions) are a pain.
But the killer at the moment is a good solution to manage and post process my raw photos. Went from Lightroom to On1 Photo RAW...unfortunately DarkTable is still not there yet. Also still missing the affinity suite on Linux :-(
Also, sadly these tools also don't run well in a VM
Also, some tools have plugins to provide vim controls for them.
I know at least and use these:
There are probably more...