Yes. Some of these are using common APIs and work on all h/w which support them. In other cases it is also inevitable that APIs will evolve to provide the capabilities needed for such tech to work.
But it is not working like that.
And there is even a clear line of evidence that the common solutions provide a worse image degradation than the properitary ones.
FSR (for all GPU's) is worse than XeSS (DP4a - for all GPU's) that is worse than the properitary XeSS (XMX) that is worse than the properitary DLSS (Tensor cores).
Here the lowest common denominator is not something I wish for.
Intels new line with Xess2 is also going properitary, running on their version of "AI cores".
Most likely because Intel thinks they can surpass AMD and match NVIDIA in the entry card space.
(And why they are eating their margins to offer mor eRAM, they want to break into the market, so they have to sweten the deal).
NVIDIA's Ray Reconstruction is also better then any alternative.
The lowest common denominator is not something I wish for here either.
Vulkan (open source) also apperas much more fragemtned then DirectX (properitary) in regards to a lot of vendor specific extensions.
As far back as I can remember (ATi's "TruForm") vendors have tried to leverage their technological innovations to be "better" than or distingush themself from the competition.
Then we as consumers vote with our wallets.
So from my perspective, the vendors aregoing in the opposite way of what you are suggeting