Many brands of TV's and other AV components have had discrete on/off codes for many years - if you could find them!
I'd heard that. I was never able to get the shortcuts to work.... myself. And I've played around with remotes and IR A LOT.
When I built the Home Theater.... I quickly realized my wife couldn't use it (just too complex).
So that is when I got a Harmony-Logitech remote... and used the PowerMid IR remote devices along with X10's IR to PLC (IR543) plus a CM15A..... and could run everything by simply pushing the "watch a movie" button.But.... switching to streaming and using Roku devices... saves me the clutter
and cost of the cable and cable boxes. And the simple little Roku remote can be intuitively operated by guests or even the tiny grand-kids.
Of course..... consumer electronics have become short-lived gadgets in today's modern-tech world. I am already planning the OLED roll-out full-wall TV screen. I am not sure where I'll put it.