Having separate dongles for network, audio, video etc. is even worse than just having specific cables for each

I guess you could use the same argument to say you're buying less when you buy your laptop. It's just arbitrary data I/O through USB with the software level interpreting it. They don't have to ship a DAC or wifi radio (if they actually omitted that) or... whatever you call the component that's part of a GPU that converts to HDMI - instead they offload that to the dongle or peripheral. In effect your device is just slowly being whittled down to a processor to USB bridge.

The headphone and USB ones are the ones I hate the most. My "flagship" phone doesn't work with any of my ~15 pairs of headphones (mostly earbuds but a few actually nice ones) without an adapter. Booting up a laptop into a nix OS that doesn't have wpa_supplicant etc. installed, no ethernet dongle or ethernet port, that's about to be annoying.

This is more about laptops/phones than desktops btw. Normal sized desktops usually still ship with every port, plus one or two USB-C's these days.

I think the point was universal dongle with universal BLE / radio protocol. It could still have different encryption schemes and keys for each device / manufacturer by upgrading / installing drivers (so in software), but at least the radio packet protocol would be the same which would keep the hardware universal. Kind of like how smart home hubs (WiFi +/ Zigbee +/ Bluetooth +/ 433MHz / etc) work.

But we all know how creating a new "universal" protocol goes from experience (ie USB "standards").