[zeveb]

That is not an argument for more non-modifier keys; it is an argument for more modifiers. Why? Each added non-modifier key adds X more modifier+non-modifier keybindings (e.g. C-n) and X-1 more modifier+modifier+non-modifier keybindings (e.g. M-C-n), where X is the number of modifiers. In practical terms, a keyboard with control, alt, shift and super only gets four two-key and three three-key bindings with each additional key. That is not great.

Adding a modifier, OTOH, add Y modifier+non-modifier and Y modifier+modifier+non-modifier bindings, where Y is the number of non-modifiers. So adding a hyper key means adding , say 104 additional keys (on a keyboard with 52 non-modifier keys). Adding a compose key means adding … another 104 additional keys.

My current keyboard has control, alt, super, hyper, compose and shift. A lot of folks add raise & lower, for even more modifiers.

[kps]

> My current keyboard has control, alt, super, hyper …

Assuming USB HID, how are you distinguishing extra modifiers?

[vel0city]

For many, additional modifier keys means keyboard firmware changes with macro programming. My keyboard does not have media keys, but I have programmed the keyboard that Fn+Q sends the Volume Up key, Fn+A sends Volume down, Fn+W sends Play, etc. There is no Fn key in the HID specification (at least not that I'm aware of), the Fn key exists only on the keyboard's firmware.

Many keyboards these days are getting quite fancy. There's even an open source keyboard firmware standard. https://qmk.fm/

[zeveb]

I use X11 and a custom keyboard firmware: both of my hyper keys generate USB left super and both of my super keys generate USB right super (or vice versa), and X11 turns left super into hyper and right super into super.