Just open them and leave.

I also hate the self checkouts because of the cameras. They can't handle anything reliably that isn't 'take from side a, scan, place on scale'. You do anything tricky like try scanning two of the same item and they straight-up accuse you of stealing a $3 packet of timtams.

I've only had the gate fail to be open on me once. I just opened it and left. It doesn't mean anything, it's just theatre. They're designed to be openable otherwise we have fire safety issues.

Unless I'm buying 2-3 items, I almost never use the self checkout.