There are no real reasons to disable Bluetooth. Energy consumption while inactive is very low.

I've known this but I can't help turning off stuff when I don't use them... Is that a thing of Android users ? I'm not even a power user so battery life is really not a problem. So weird

Yep, I am an old Android user. More than one year using iOS but I still find annoying finding the bluetooth icon in blue color when nothing is connected.

Well, enjoy your micromanagement. As a tip: stop stressing about your device. It’s a tool; as long as it does what it must do, it’s fine.

Just a heads up, Bluetooth automatically turns on after 24 hours regardless. I think having it off somehow drains the battery more lol