mc adheres to NC standard, so you already have an extremely accessible system. The whole UI knowledge can be transferred easily among mc, TotalCmd, or NC from 1988 or whatever. Not the case with most TUIs. I had to use aptitude and git's text mode merge tool recently, and both had terrible accessibility, not to mention entirely different designs too. I'm sure I'd get good at them once I read their manual but they were extremely non-intuitive and hard to explore.

admittedly mc is far from being a "modern" TUI