They can't improve openCL. They can make suggestions or proposals, but because broad compatibility are the priority, most of it wouldn't get added. They'd be stuck with a worse instruction set with tooling that spends half its time trying to figure out all the different hardware compatibility you have to deal with.
Cuda is better than openCL. Gsync was better than freesync (though the gap has closed enough that freesync is viable now). DLSS is better than FSR. None of them are small advantages, and they were all created before there was anything else available even if they wanted to. Supporting any of them in place of their own tech would have been a big step back and abandoning what they had just sold their customers.
It's not "pro consumer". It absolutely is "pro technology", though. Nvidia has driven graphic and gpgpu massively forward. Open technology is nice, but it has limitations as well, and Nvidia's approach has been constant substantial improvement to what can be done.