>>4442365But small lenses exist for sony, and the smallest lenses on other brands are fucking horrid and literally unusable for video due to focus breathing by over 5mm worth of focal length and audible focus motor noises combined with a focus by wire design that requires running the motor.
In fact, if you add the filter threads back to nikon's shitty pancake, it's the same size as the 35mm f2.8 ZA and samyang 35mm f2.8
The actual problem is mounts are too shallow. Sensors have to be set further back into the body to make good (aka rear focusing) pancakes. With these shallow mounts used by canon, nikon, and sony, a GOOD pancake under 35mm is not actually possible. Shallow mounts are absolutely ideal for making the sharpest possible pro zooms and fast primes because the rear element can be huge, but for small lenses desired by artists it's absolutely not possible for RF, Z, L, or FE mounts to support a good pancake and it's a small miracle sony got lenses like the viltrox 50mm f2, sigma 90mm f2.9, etc.
In the end leica M mount cameras are expensive because japan failed so hard everyone still wants one, and germany can only make so many. There is no real better option among the japanese brands. Only different flavors of worse. If you want a mount that prioritizes lens designs actual photographers want, you need to go to leica M.