2.4GHz Dongle vs Bluetooth
A dedicated 2.4GHz receiver delivers latency close to wired. Bluetooth adds noticeably more delay and is the connection to avoid for competitive play.
A 2.4GHz gaming dongle runs a proprietary protocol tuned for one job: getting input to the PC as fast as possible. Manufacturers optimise the polling and pairing behaviour specifically for latency.
Bluetooth is a general-purpose standard built for compatibility and power efficiency across many device types. That flexibility costs responsiveness, and the exact penalty varies by device and host adapter.
Many peripherals now support both, letting you use the dongle at the desk and Bluetooth on the move. Some headsets can even run both simultaneously — game audio over 2.4GHz, phone audio over Bluetooth.