To be fair, phones are able to take high quality photos due to the software AND hardware implementation. Their cameras are linked directly to their processors and have hardware dedicated to processing the actual image and the actual lenses are improving every year... so the software isn't doing ALL the heavy lifting.
Cameras smoke Laptops cause Laptop Cameras still have to go through the snail pace USB header.
And bespoke cameras are far better than either webcams, laptop cameras or smartphone cameres. But for the average consumer, the smartphone camera is good enough. And RTX is a bespoke camera. Hell, I'd go even as far as to say that the primary use-case for RTX is not gaming, but science.
RTX having hardware dedicated to the calculations typically found in ray traced light is going to be a better solution than something purely software based. Crytek found a way around it and has ray tracing working on non-RTX cards even in DX11 but you still get the best performance out of cards with the RTX Cores.
Is it though? RTX is a solution in the hands of nVidia, forcing game devs to optimize their game environments to the hardware. Software RT is in engine and thus in the control of the game devs, allowing them to optimize their game environs in general. There are some indications that high level HW RT is not necessarily better than lower levels.
Software RT is going to be easier to work with and grant more artistic freedom as well. The same exact thing happened with PhysX or Hairworks, for some more recent gimmicks.
There will ofcourse be hardware acceleration, but there will not be a bespoke edge for nVidia. Because the difference with generic acceleration and bespoke acceleration will be indistinguishable for majority of consumers. Already the actual difference between software RT and hardware RT is almost non-existent.
And finally, as the technology is optimized, it may just become cheap enough on the hardware that brute forcing it, without any bespoke hardware is the way to go.
Unless ofcourse we switch from rasterization to raytracing as the basic way of graphics processing. But in order for that to happen, you would need HW RT to be generic.
[edit]:
After some further research, I chanced upon path tracing. Which seems to be - so far atleast - a software based iteration upon raytracing.
Check it out;