No it can never be the same. The terminal is about not having to switch from the keyboard. My entire workflow is tmux panes with different TUIs and terminals. Not to mention performance, with a neovim IDE you may have tens of them open in different panes for example. I wouldn't try that with VSCode.

You can make even lighter weight and just as keyboard driven GUIs. The only downside, as you say, is them not integrating with Tmux.