What I am uncomfortable with is the inability to run Wayland on older video hardware. X11 will happily run with Vesa driver on older hardware which no longer has functional 3D accelerated drivers.
What is the way forward for the retro community to run a modern Wayland system on older hardware?
Hopefully someone more knowledgeable can chime in or correct me
Software compositing is possible. Wayland doesn't strictly require hardware acceleration or operations that are hopelessly slow without hardware acceleration.
Wayland compositors can use llvmpipe: https://docs.mesa3d.org/drivers/llvmpipe.html
That being said, your bigger problem is trying to view modern websites on 1080p displays on that ancient hardware...
How old? Im running KDE on 6700k and gtx 960. (I can run on without 960 too). Thats 10 year old at this point
If your Linux distribution is handling Mesa packages correctly, you will never lack OpenGL/Vulkan drivers.
The reason is that Mesa includes "software rendering" drivers for both OpenGL ("llvmpipe") and Vulkan ("lavapipe"). As the name(s) might suggest, they use LLVM to JIT shaders for your CPU (supporting SIMD up to AVX2, last I checked - although typical compositing shaders tend to get pattern-matched and replaced with plain `memcpy`s etc.).
So you should always be able to run a fully-featured Wayland desktop (albeit limited in performance by your CPU), on any unaccelerated framebuffer, nowadays (and I remember doing this even before Plasma 6 launched, it may be older than usable Wayland desktops tbh - the Mesa code sure is, but maybe distros hadn't always built those drivers?).