There are very few actual Bluetooth mice offered by a major vendor in a full-size format. They're pretty popular in the "laptop mouse" market where the mouse is made uncomfortably small for people who care more about portability than usability, but the majority of full size wireless mice use proprietary RF protocols rather than Bluetooth.
A Logitech G rep once explained it to me, Bluetooth is technically capable of equaling USB mice but a lot of the Bluetooth adapters included in OEM PCs are hot garbage, so reliable performance is hard for them to achieve. That's why their last Bluetooth gaming mouse actually shipped with its own adapter built in to the charging base.
People who enjoy latency free and battery free mice. If its at a desktop there is really no reason to not use a wired mouse. And a wired keyboard is basically essential since bluetooth doesn't work before the OS has booted.
While you're correct, there's lots of plain-RF wireless mice and keyboards that work just fine before the OS loads, and many people confuse "bluetooth" with "all wireless".
Plus, some wireless mice are actually faster than some wired mice.
There's one reason: one less wire to deal with. I bought a Logitech G703 just to avoid the clutter and tugging on the cable when using it (and not having to buy or build a dampener for the cable). It has a cable I can use to charge it or use when it's low on charge, and I can't notice any difference in latency when it's wired or wireless, or compared to any wired mouse I've ever used. I'm also not playing many FPS, and definitely not anywhere near a competitive level, so even if there is some measurable latency it simply makes no difference to me.
The wireless dongle is plugged into a USB port on my monitor so it's only about a foot away, though not quite direct LOS. And if I wanted to fork over $100 for Logitech's wireless charging mousepad, I'd never have to plug it in again. I probably won't, but it's an option.
TL;DR: wireless and wired gaming mice have the same response times, but normal wireless office mice have slower response times than their gaming counterparts.
My biggest issue with wireless office mice is that if the laptop de-prioritises bluetooth interrupts due to CPU load or whatever, then you get this really laggy response. I'm not entirely sure exactly what's going on, but if I open something heavy on my work laptop the mouse will have a 0.5-1 second delay in responding.
This doesn't affect the touchpad, which I presume is running over a different protocol that has more real-time interrupts.
Anyone for whom the phrase 'I have to charge my mouse' sounds insane.
I have no devices using wireless protocols where a wired alternative is feasible. Why would I ever want to deal with the pain of wireless when cables are so easy to use?
My wireless mouse has a removable cable so I can charge and use it at the same time. It takes about 15 minutes to charge fully. It's really not that insane.
99% of the time I get to use my mouse with no cord dragging around, and it's never died on me because I can just plug it in when necessary.
