Bluetooth is too flaky for such critical inputs. Dongles will usually bring higer polling, less interference/2.4Ghz connectivity and lower load on the host system. Sadly most are USB-A plugs.
Bluetooth being cnstantly used for audio and so many other things as well might also be at play ?
Isn't that more due to the Bluetooth hardware used and implementation on the OS side? On macOS I never had flakyness with Bluetooth keyboards but on Windows my experience was significantly worse.
It might as well be, though Bluetooth is kinda hit or miss in general IMHO.
On Macos, first party peripherals have of course pretty good connectivity (is it even straight Bluetooth?) but it's not perfect either, and third party ones have a tougher time.
Bluetooth being cnstantly used for audio and so many other things as well might also be at play ?