Do people actually get on the wrong flight when travelling?

I don’t think it can be done. The amount of checks that are carried out nowadays together with electronic boarding passes means that people should be denied entry to the flight at the gate. I suppose that if the electronic check should fail there might be a possibility of the wrong person being let through, but that would be quite rare. There’s probably exceptions for people with missed connections and they have to take a transfer on a different flight, but they’d probably follow the same boarding process. There’s also the possibility of human error where the scanner is too sensitive and what should have been flagged as an error doesn’t record a boarding. I did make a dash for a gate once as I heard it was the final boarding call, only to realise upon reaching the queue that it was the same destination but a different flight. But that was the closest I’ve been to boarding the wrong plane.