I'd like to add my voice to the chorus requesting Linux versions of Affinity software.
I'm in the process of migrating from the Mac to Linux, and one of the few stumbling blocks is around photography software. As a Capture One / Affinity Photo user, it's disappointing that neither is available for Linux, although Capture One's FAQ coyly answers the question with "Currently, the Capture One software is only compatible with macOS and Windows.", which at least gives me hope for the future.
As with some other commenters here, I'm being driven away from Apple by their expensive, locked-down hardware and some odd design choices, e.g. the keyboard fiasco and the touchbar on the MBP.
I've looked at Windows 10 but it's as ugly as ever and has too many privacy and security problems.
I've used Linux off and on since it's earliest days, and every few years I would reevaluate it to see how it was maturing. The last time, a few years ago, I had too much difficulty with driver support and HiDPI displays to persevere. However the maturity of recent distributions has prompted me to look again, and I like what I see.
GPU hardware support has matured greatly, and thanks to Vulcan and Steam, Linux has even turned into a capable gaming platform. I'm not surprised to hear other commenters say that it's the standard platform in the VFX industry.
Hardware vendors are getting on board, with Lenovo and Dell providing certified hardware, System76 creating capable laptops and workstations running their Ubuntu-derived Pop!_OS, and in Europe we have the likes of Tuxedo creating Ubuntu and Manjaro-based laptops.
As other commenters have noted, the introduction of Snap and Flatpak has greatly simplified the question of app distribution, and virtually all of the leading distributions now support both formats as standard.
I've decided to make the jump. I've moved to cross-platform versions of most of my software (e.g. cloud drive, password management, browser, note-keeping, office apps, productivity tools) and the process was much less painful than expected. I'm currently running both a MacBook Pro and a Linux laptop in parallel, and later in the year I plan to drop the Mac entirely and build a decent Linux workstation.
I really hope that Serif will give an indication that they are willing to join me on the journey. If not, I'll make do with Darktable and GIMP/Glimpse while I wait for something better to come along.