I think there's 2 potential issues with earbuds, the Bluetooth connection itself and/or a pairing app for the buds.

As for the Bluetooth connection, I've never read about security concerns. I don't think recent versions of Bluetooth are at risk of leaking data. They might be somewhat leaky in metadata (which devices are sending signals at all).

The pairing app poses imo a larger risk. These apps are usually proprietary and might be trying hard to get information. That's a risk with any app that requests many permissions, though. A simple solution would be to not use the pairing app. Or you might look into compatibility of your device with Gadgetbridge, which is open source. https://gadgetbridge.org/

Not a dumb question. Personally, I would recommend the most current version of Bluetooth you can and update your phone (if that's what you're using). Emerging versions are Bluetooth 5.4 and 6.0 and they're backwards-compatible. Thus, they'll fallback to the lowest version supported by both devices.

EDIT: Here's the section on Bluetooth security:

https://en.m.wikipedia.org/wiki/Bluetooth#Security

Galaxy Buds = privacy hell.
If you want to change settings (like a better equalization),
the app needs almost all privileges (like SMS, phone, location, notifications, etc.)
and it doesn't work with 3rd party ROMs.