They are the most distributed since I think only Unicomp has patent rights on buckling spring switches (if they're still valid).
Buckling spring patent is expired. However, Unicomp purchased both the IP and the tooling to produce it. Technically another company could make them, but the R&D required to create new tooling isn't likely to be cost effective when compared to using off the shelf parts like the Cherry MX family.
As for the other aspects, it's hard to say. Cherry MX has a significant availability advantage, and offers a rather nice lifecycle of ~50M+ operations. Unlike Topre, any manufacturer can use Cherry MX as well - there's no licensing required and zero special tooling. (If you can make motherboards, you can make Cherry MX PCBs.) Even if you can't repair one, you can replace one, it's easy to find parts, and a number of other switches copy the Cherry pin dimensions to give manufacturers flexibility. It's entirely legal to match the pin layout.
The downside is that it's also made it easy to make knockoff Cherry switches and there's likely to be a number of convincing forgery parts out there as well. Part forging is a truism on high dollar, high value electronics parts as a whole - and sometimes the forgeries are virtually indistinguishable from the real thing.
But from a volume manufacturing standpoint, Cherry MX actually is the best switch on the market currently. It has the combination of highest availability, it's a medium cost part, it offers the greatest flexibility within a single line, and has the lowest estimated failure rate.