In other words, it's a big mess.
The argument for having the same connector for everything only works when you can plug in a cable and it just works.
If I need special cables and capabilities for this, that and the other let’s just go back to having different cables so it’s at least obvious when we’ve got it wrong.
Yes it took far more research than ideal, but I have a TB3 dock currently charging my computer, connecting a mess of USB peripherals and connecting to my 4k monitor at 60 hz using only one single cable and port, and it's wonderful. Totally worth it.
It was rough at first when I picked it up last year. However the driver updates in Big Sur seem to have fixed my complaints, particularly with the MBA that almost never worked.
It works pretty well now. I unplug my work laptop and swap it for my personal one when I want to work on personal projects, and things just work.
My biggest complaints about this dock now are that the fan is loud, and it only charges at 60w. I worked around the noise by attaching it to the underside of my desk, so it's pretty hard to hear now.
No reliability issues whatsoever, despite me switching the dock between my work laptop and a personal laptop almost daily. The dock is connected to a bunch of peripherals, as well as 2 external monitors (one 1080p, another 4k@60hz). Only one cable going out of my laptop (connecting the laptop and the dock, as the cable connecting to the dock also charges the laptop at the same time).
Now we're a few years in and seeing a USB-C port just fills me with dread cause I know I'm gonna have to do research. And I yearn for the days where if I'm hooking up a monitor or something, I see an HDMI port and know exactly what that port is for and what kind of cable plugs into it. Seeing a USB-C port in something could mean any number of things.