For example, I can't think of one RAW image processor from the original manufacturer that's available on Linux. Honestly, if there was, it would actually be a good reason to switch to that brand.
Also yes, I'm aware of RawTherapee and DarkTable. I use RawTherapee regularly, it's absolutely excellent and I highly recommend it, but it's also absolutely useless for certain use cases.
Nowadays I tend to use linux apps on Windows, thanks to WSL. For example, Windows' file browser crashes frequently on my setup, so I use Dolphin instead.