The big deal is that vscode uses a client/server setup, where a "client" vscode instance runs on your machine and a "server" vscode instance runs on the remote one. Then they figured out how to make latency and/or network intermittencies a non-issue. The experience is basically the same as working locally, except the linter, language server, formatter, and compilation run on the server-side (and hence don't bog down my laptop in this case).
Then there are quality-of-life touches, such as vscode offering to tunnel ports whenever you launch something in the integrated terminal that listens for connections. That is: let's say I run "python3 -m http.server" in the terminal within vscode (where I'm working on a remote project). The http server is launched on the remote machine, and I get a prompt asking me if I want to setup a 8080 (laptop) -> localhost:8080 (server) tunnel.
I was an adept of Jetbrain's various IDEs (and smart completions are still better there for most languages), but vscode-remote works so well that it has won me over.
Not long ago, a friend of mine was considering a new laptop. He was happy with his pixelbook in general, but working in the "c++ with lots of number-crunching" space the pixelbook wasn't cutting it. I gave him an account to my desktop machine to let him try, and he's now a happy owner of a nice workstation for much less than what the laptops he was considering cost. Important point: my desktop uses a residential connection in Spain, and he's in the US. He had 0 issues with latency whatsoever (and I can attest the connection itself does have such problems).