Should I do factory reset after buying a used MacBook Air?

evolvingfaster wrote:

Thank you again ! I hadn't thought about "find my...." I'll do my own reset and then proceed with restore from Time Machine. Means: reloading OS does *not* substitute for reset. Clean is clean.

You are not paying attention to what users are telling you. The seller must do this: What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

If the seller does not do this the computer is of no use or value to you. You doing a "reset" reinstall will not accomplish what the seller needs to do.

The original owner needs to do this BEFORE selling it:

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

If they don't, you may end up with a useless boat anchor.

Good luck with that. If they are still signed into Find My on that device, when you reset it, you're going to end up with an expensive paper-weight.

You can NOT bypass the activation lock.

If they do not follow the process above, you may end up with a boat anchor when they decide to kill it using find my.