BT is just a disaster everywhere. My experience is that for "normal" use cases (input devices & headphone audio, basically) Linux is no worse than anywhere else, but still bad. Apple users think it's great because Apple made AirPods work, but that's a testament to Apple's integration engineering and not the underlying technology.
> Plugging in a new display doesn't immediately work
I haven't seen this with Intel drivers on a major distro in a long time. But yes, the driver story for other hardware remains somewhat weak. And obviously the farther you get from "Gnome on Ubuntu/Fedora" into the weeds of desktop choices, the weirder the feature set is going to get.
> A USB microphone fails to register as an input sound device
No idea here. I haven't seen a USB audio failure in a LONG time (closest I can think of is a Razer headset that has two chat/game output streams and Linux sees only one by default). Mostly likely you had a broken piece of hardware that worked in windows only by installing its own driver. And that sucks, but poor standards compliance is just something we all live with.