Surely they charge the keyboard and mouse. Wouldn't at least one of them be charged via a USB cable? Plugging that to the computer would turn the peripheral into a wired USB one.
Jokes aside, not all bluetooth devices turn wired once plugged in. I know my MX Keys USB-C port is only for charging, for example.
Lol yeah that design is really baffling!
That said, it's still possible. The charging port is near the back edge of the mouse (the side closer to the user) whereas the sensor is on the other end. It won't be comfortable but letting the cable hang off the edge of the desk should allow you to use it to turn bluetooth back on. :)
It charges to full in a couple hours and lasts at least a month on a full charge so almost everyone has plenty of opportunities to charge it at times when they aren't using the computer.
If you do let it get low enough that it might die it only takes a couple minutes of charging to get enough charge to last 8 hours. Start charging and go get a drink of water or visit the bathroom and when you get back it is ready for the rest of the work day.
That said, from what I've read there either is no warning when power gets low or it doesn't always work. With it only needing charging every month or so I can someone forgetting. It is possible to make a script to check it and give an alert if it is low, and make a cron job run that script [1]. That really should be built in.
[1] https://dev.to/samselfridge/magic-mouse-low-battery-alert-4m...
Which is very short compared to other mice: Logitech's (and mostly everybody else's, I assume) Bluetooth mice last for several months, some last for years on a single charge. I suppose it's not a fair comparison in that the Apple mouse does more? But they still suck in terms of runtime.
The 0.01% who manage to find themselves with an empty battery will be slightly inconvenienced for two minutes while they charge it up enough to get to the end of their day.
• Hit ⌘-space to open Spotlight.
• Type enough of "bluetooth file exchange" to find the Bluetooth File Exchange app and launch it.
• Bluetooth File Exchange will see that Bluetooth is off and give you a dialog offering to turn it on, with turning it on the default action, so just hit return and Bluetooth will get turned on.
Or, if their Mac supports "Hey Siri" and it is enabled, "Hey Siri, Open Bluetooth File Exchange".
My point is that you do not need to get your mouse connected in order to turn on Bluetooth. You just need to get one of {keyboard, mouse, trackpad} connected.
I haven't been super happy with the rechargable AAAs I've used, so I might prefer specific batteries for smaller items. But most video game controllers or presentation remotes or wireless keyboard and mouse have plenty of room for one or two AAs