I'm excited about BLE for the browser. I'm not sure what multiplatform (mobile & desktop) alternatives there are except for Qt, and even Qt has bugs and open issues you have to work around.
For instance, only Qt 5.13+ has support for discovering and connecting BLE devices on Windows without pairing first -- if you are stuck on an LTS version (5.12), BLE is awkward in use.
For instance, only Qt 5.13+ has support for discovering and connecting BLE devices on Windows without pairing first -- if you are stuck on an LTS version (5.12), BLE is awkward in use.