BTW if your using TB3 as your main connection to your laptop I highly recommend a magnetic TB3 adapter. This has been working great in my setup for over a year and makes docking/undocking a snap.
https://www.amazon.com/Magnetic-Thunderbolt3-Connector-Trans...
With TB — can you literally just unplug from one Laptop/PC and connect to another and everything is back up and running on the 2nd computer?
It’s still early days so compatibility isn’t super yet, as this discussion shows. Also, being USB, there are many possible subsets and no such thing as a “universal cable”. The silicon is still immature and the analog issues are fiendishly complex.
The cheapo vendors will implement the minimal standard (or less). The higher end devices will be more compliant, but bugs remain (as I said, still early days).
But last year I switched to buying type C devices whenever I had the choice (even electric toothbrush) and so far it’s been fine.
I kind of wish there were manual/dumb TB3 switches for this sort of thing but I have not seen any.
I have a TB2 dock which I connect to using Apple's TB3 to TB2 adapter. I keep my Time Machine backup drive connected to the dock (along with 4K monitor, keyboard, mouse, and speakers). If I don't eject the drive before disconnecting from the dock, macOS complains about disconnecting the drive without ejecting it first.
For what it's worth, I didn't find this to be, well, worth it. I got a razer egpu enclosure and while it was certainly very well engineered, it was comically over-engineered. Weighed something crazy even without my gpu in it, I wanna say 10lbs, maybe even 15. Plus, it was huge, as big as an itx case. Then I had to drop 60$ on a long enough thunderbolt Cable to let me have the case under my desk.
Then there was all the issues with plugging in a laptop. Windows on a lenovo x1 carbon worked fine, with plug in/out capabilities. Ubuntu 18.04 on same machine wasn't plug and play, but I got it working after about an hour of fiddling. Never got plug in/out working. Plug in worked, but unplug without shutting down lead to a crash.
All this and the enclosure was like 300$, and I was bottlenecked by my laptop processor anyway. In the end I think it's just simpler to buy that expensive graphics card you're looking at, then build a simple pc around it, and then make use of some kind of network based workflow for data sharing (git server for your code, networked hard drives for video, photo, music editing etc. Much easier, much more flexible, and imo in the end cheaper.
This is why mostly you get a box to house all that.