FSR2 splits the market the least since it can run on any GPU, unlike DLSS which wouldn't be able to run on the console versions (so they'd have to add and optimize for FSR2 anyway; extra work for little benefit).
Sure, you can, but if one technology is both "good enough" and "works on everything" I can understand why the developer might only bother with that one. Proprietary, vendor-locked standards leave a bad taste in my mouth.
I would like to at least see XeSS implemented in addition to FSR2, as it's another open standard. With any luck, pressure could be put on Nvidia to make DLSS vendor-agnostic as well, but they've proven over and over again that they really don't care about gamers.