I have a number of the Cherry MX Board 1.0 TKL that has a backlight, I use them on keyboards for computers at theatrical (stage) shows. No need to turn on a light that may get noticed by the audience to see where the keyboard is or to find your place on it.

And some people do not 100% touch type, or don't touch type in the strict way everyone expects all touch typists to do so.

To type, sure. But what if you want to press a more obscure button like F7 or Print Screen? Also helps for games where your fingers aren't always in the standard ASDF position and you're still learning the keybindings.

i have a moonlander keyboard that’s programmable. certain keys can trigger layer shifts, and backlighting helps me know which layer i’m on.

I'm pretty confused about your comment and all the replies. Do you all not have lights? I can see my keyboard just fine without backlighting. Not wanting backlighting has nothing to do with whether I need to look at my keyboard or not. I just think it's ugly (which is just a preference, totally fine for people to like it).

Yes, controlling your lighting situation is certainly a good solution. For me, even though I don't compute in the dark I do keep the ambient light pretty dim. I get sick of squinting at the keys.

If you've memorized `~!@#$%^&*()-_=+[{]}\|;:'",<.>/? then yeah, you don't need a backlight. I've memorized some, but certainly not all.