I think it’s perfectly possible to use Mint, Ubuntu, or Fedora without the terminal. But a lot of online tutorials are like, “Just run this command.” because it’s faster.
I’m an experienced terminal user but I know with my Steam Deck, I barely ever use it. Really the only time is when I want to update packages quicker than using the GUI tool. But you could successfully use a Steam Deck without ever launching into Desktop mode, much less opening a terminal.
In fairness, I can’t keep my kilt down.