It's feasible, but crop cameras have much smaller/dimmer VFs than film SLRs. Fresnel and split image screens helped but they weren't absolutely necessary, I used (still do sometimes) plain screens a lot of the time on the F2. You can get Katz Eye screens that restore some of this functionality but I've heard that there can be problems with metering? FF overcomes the problems, but at a cost way beyond my reach!
I've read that the old manual SLRs had the brightest VFs, because there was no loss of light to the AF system but I don't know if there's any truth in this. I've never used an AF film SLR. Of course, in the glory days of the manual cameras, a lot of people used primes which were a lot faster than the zooms that are popular now.
The VF issue is a pain, and I'm still convinced that the manufacturers could find a way to get past it if they really wanted to, but most people coming into photography now have never used MF cameras, so there probably isn't much demand for this.