USB-C on a PC monitor can potentially mean more fast DisplayPorts, nice to have in your multi-PC setup. It's PC master race stuff, really.
I expect most USB-C ports are crippled - like everything else - on most mobiles.
That makes them a nuisance that I need to buy adapters for, wasting my time without worthy benefit.
But at least they finally solve the problem of pluggage
(at least at one end)