I wonder what they'd say in response?
For me, a lot of the value is in having a single app that I can turn to for most of my dev tasks. That app happens to be a terminal (with different projects contained in different tmux sessions).
It gives something very close to the "hands never leave the keyboard" experience that I like about living in the terminal, while also letting me fall back to a mouse when that would be quicker or easier. It also gets me the nice things that I expect are only possible to do well in a graphical environment, such as minimaps and displaying graphical information like plots or dependency graphs.
I do find that my text-mode editor skills are weakening over time, and that does have an impact on my productivity when I have to do a decent whack of work on a remote server. But that's not something that I personally have to do often enough to be a major concern.