Sony may not be producing much in the way light-drinking lenses like the f/1.2s, but the best lens on Sony right now is the Sigma 35mm f/1.2. I shoot an R5 now, but I'd give two of my RF primes for that one Sigma. Yeah, I think it's more difficult to make that sort of thing with the e-mount, but it's certainly not impossible. If that system had a 35mm (which it does), a 50mm and an 85mm f/1.2, then I think the issue is a bit mute.
Just on the Sigma 35mm f/1.2, the Sony GM 35mm f/1.4 is sharper. There are Canon EF f/1.2 lenses, but these are rather rubbish on the sharpness and Canon had to make the newest EF 85mm f/1.4. Like the Nikon S f/1.8 lenses are all sharp, the Z 50 f/1.2 is sharp wide open, the RF 50 and 85's f/1.2's are all sharp and near optically perfect. I do think Sony can still make f/1.2 lenses, but I think they'll always have a compromise of some sort on the Sony side.