And this is pretty much why for the last decade I’ve had virtually zero fucks to give about Bluetooth draining my phone’s battery. The difference tends to be limited if your device doesn’t suck.
Unless you’re optimizing for the worst case scenario: like fifteen minutes of phone charge is going to make the difference between getting home and sleeping at the airport kind of scenario. Pressuring you actually use it for something: it’s simply more bother to diddle Bluetooth than to charge normally.
Which also reminds me of why I use a Bluetooth speaker at work instead of my tablet’s speakers. For comparable volume blasting my tablet’s four speakers all day sucks down more charge than running the Bluetooth speaker.
Rather the real train to turn off Bluetooth IMHO is because you’re not using it more than a handful of times a year, or to limit your exposure to some one in a ten million asshats trying to spam you with pairing requests, lol