When files need to be shared between two computers, whether at office, home or conference, major operating systems have peer-to-peer file sharing built in.
Windows Nearby sharing uses Bluetooth only, which means file transfer speeds are a tiny fraction (far slower) than even 3G tethered internet. Windows Nearby has the advantage like other operating systems of not requiring internet, but the real-world file transfer throughput is on the order of 1 Mbps, due to the limitations of Bluetooth itself and interference from other 2.4 GHz devices, even when the two laptops are less than 3 meters apart.
Windows Nearby file sharing is generally not practical for files over about 10 megabytes, due to the transfer rate of about 100..200 kilobytes / second in real-world use. That is, a 10 megabyte file takes about 2 minutes to transfer using Windows Nearby.
Apple AirDrop is much faster than Windows Nearby since AirDrop uses Bluetooth to negotiate a peer-to-peer WiFi connection that doesn’t rely on WiFi AP (router). Depending on the RF congestion and the nature of files transferred (few large files faster than many small files) the data throughput of AirDrop can be in the 100..500 Mbps range, 100 times faster than Windows Nearby sharing. It would be very beneficial if Windows Nearby would use adhoc WiFi like AirDrop.
The deprecated Android Beam used NFC to negotiate a Bluetooth connection, which was very slow like Windows Nearby. Android Nearby is reported to a possible feature in Android 11, ChromeOS and Chrome browsers. We will hope that Android Nearby will use WiFi like AirDrop for useful speed.