Blunt question I know but this is something I found a bit hilarious and baffling because I'm someone that's fairly adaptable as a gamer and for the most part I'm not that bothered about keybindings these days and being able to rebind them. Some people seem to get really bothered about it though and I was seeing on places like steam some absolute sperg sessions about it.
Do you care about this sort of thing? If the layout is pretty normal with WASD and such I don't understand why people would care that much so I'm trying to go out of my way to understand. One repeating trend I saw weirdly was left handed people complaining about it. My argument is this, there's only so many ways one can rebind the keys when it comes to shortcuts, so I can understand doing it for certain actions, but otherwise it seems silly.
Depends on the game. For example key binding in fighting game can go a long way to alleviate wrist strain by rebinding to the numpad instead of the usual J K L and stuff.
Rebinding a game like Star Citizen which has a lot of binds and you can make a lot of those binds be alt+ something also helps a lot to have most things in your default hand position instead of having to move your hand about.
If it's something simple and the keybinds aren't too bad then I won't really care. That said it's always nice to have the option.
Sometimes also you just want to unbind something you'll never use.
Example, in Chromium browsers ctrl-d instantly adds a bookmark for the page and then you have to click on a popup to remove it. If the site was already in bookmarks I don't want to remove it.
This is really close to ctrl-f which I use a lot so I accidentally press ctrl-d way too often.
Browser doesn't have any way to change its built in keybindings, but Disable Keyboard Shortcuts extension at least lets me override it with nothing.
One thing I noticed some devs do which seems more viable than keybinds is simply offering slightly different layouts or doing keybindings for specific keys that somebody might definitely want to change. Some things I've seen with a quick search are completely bizarre and I question how people can even play like that and didn't know it was a thing lol. Numpads I get for a space sim and stuff but definitely worth researching this one.