> Mainframes survive, but serving a much tinier portion of the market than they used to.
I would argue mainframes rebranded to "cloud" which is ubiquitous and more people interact with this computer than any other type of device... only difference is that it's a browser instead of a terminal
There is constant shifting between client and server computation. I think it is a stretch to call cloud servers “mainframes”. There are still old school mainframes, running JCL, and old school mainframe DB2 and COBOL. That ain’t cloud.