Generally I’ve only been unlugging my work laptop from my desk about three times a week but for work-life hygiene I should probably unplug it at 5pm 5 days a week. Since it’s mostly split across 2 laptops and occasionally a third, I know the cable will go but haven’t thought too hard about the laptops so far.
TB monitors mostly means I’m wearing out one connector instead of three (can you wear out MagSafe?) so it’s an improvement.
You seem to be asking about a solution where you don’t have to move any cables? I’m not sure I have enough TB3 ports anywhere to do that. Someone with a complete TB3 system might be able to put one computer at each end of a chain, but I think you’re right that they won’t play nice, and you could never go to three. Docking station or KVM switch are probably it.
I wouldn't want to wear out the slot in the expensive monitor, but rather have a short extension permanently attached just for manual cable plugging purposes.
The issue is 4k@60.
Not full emulation and remaining "connected" - just the ability to press a button and change what the device is plugged into.
Edit: the only ones I could find with usb c were full KVMs and far more expensive. I would guess a female usb c to male usb 3 adapter might be a cheap workaround.