Electron apps are seldom snappy, we use it, because some plugins aren't available anywhere else.
Programmer editors with such capabilities are decades old.
As to the second, I'm unaware of a gui editor with a built in interactive terminal prior to VS Code.
Atom is slow AF, and I hated using it (same for Brackets). AFAIK, it's using the same terminal code as VS Code.
I haven't seen an integrated terminal prompt in Visual Studio (not code), you get an interactive command window, and misc output windows though.
Eclipse, hadn't seen an interactive terminal there... I guess it's another 3rd party plugin of some kind?