Bluetooth API won't give useful fingerprinting information unless the user allows it with a very obtrusive prompt.

It's not something that's useful to the majority of websites, but I find it extremely useful for hobby ESP32-based electronics projects. It gives an easy way to configure individual boards, with no weird captive WiFi portal required. It's cross-platform (Windows, Mac, Linux, Android, just not iOS), and no native app required, an an easy-to-use API. This means means a lot less development overhead for my hobby projects. And it means I can give devices to family & friends without them needing to fiddle with firmware to configure the device.