Not at the venue, no. The relevant tokens are saved locally and the barcodes are rendered on-device once you’ve accessed the ticket, which you can do hours/days in advance.
I just used (against my will) the Axs app to go to a local show. It required location services to be enabled and didn't show the random qr code until it could verify I was at the venue.
How exactly does that not work with browsers and local storage though? It seems like they're just caching stuff in the app and they definitely can do the same in browser storage.
> How exactly does that not work with browsers and local storage though?
On iOS, at least, local storage for web apps doesn't have guaranteed persistence. Safari can and will "randomly" clean up, usually if the device is low on storage. This happens less frequently for pinned PWAs but still happens.
If you need to absolutely guarantee that your thing will work on an offline mobile device, you have to use a native app.
I haven't seen a paper ticket in a long time.