Not OP but they're not saying they want to use emacs keybindings, they're saying they want to use emacs keyboard macros [1], which I agree really are a very handy feature having no equivalent in JetBrains.
Emacs keyboard macros have an inferior equivalent in Intellij (and, I'm assuming, their other products). But also, emacs just somehow feels faster. Maybe keystrokes are marginally faster, maybe it's my expectations, but there it is.
I know that Intellij has emacs key bindings, that's not the issue, I'm happy with the Intellij default bindings.
In Jetbrains products, I am CONSTANTLY hitting Esc to Tab to deal with the helpful predictive suggestion. I find that feature sometimes useful, so I have not turned it off. But it definitely produces a different and maybe slower experience than typing in emacs. Maybe there is a mental mode switch between typing and handling the hint?
I know that Intellij has emacs key bindings, that's not the issue, I'm happy with the Intellij default bindings.