Why we should design things to be difficult to use
theguardian.com
theguardian.com
Several chorded keyboards came to market in the UK, receiving plenty of press (eg coverage on an influential weekly TV technology magazine program, in the days when there were only a handful of broadcast channels). They all failed dismally despite attracting a small core of devoted fans.
You can get highly customizable mice with multiple programmable buttons etc. Only gamers buy them. I do edit video and audio for work and while I like my key combos as much as the next person and sometimes set up hardware mappings on external devices for big jobs, I don't think any of them need to be universal.