Yes because the security of barcodes and screenshotted tickets were such a huge problem before.

I think what you just described is actually a problem. Friends of my parents were visiting somewhere, bought tickets to a show from a reseller, met up with the seller (normal looking guy, no red flags, gave some plausible story why he was selling) and paid cash for printed out tickets with barcodes. Printouts looked legit, dates on the printouts were correct, etc. Went to the doors, tried to scan their tickets, got told that unfortunately they’d just been scammed. The impression they get from the box office worker is that this sort of bad news is something they’ve had to deliver frequently. Anecdotal, but I doubt those friends of my parents were the only ones to get scammed in this way. TicketMaster still sucks as an organization but the extra security of rotating barcodes does serve a legitimate security purpose, just like the rotating security codes generated by an authenticator app.

Airlines have recently been having problems with stowaways using screenshots of boarding pass barcodes or QR codes too. Such stowaways should get caught before departure by passenger headcounts or boarding ID checks, but clearly there are gaps or breakdowns in these procedures because some of these stowaways are getting caught at the destination. Others may have successfully flown for free. If it keeps happening I bet we’ll see rotating barcodes come to mobile boarding passes too, if that hasn’t already happened.