This is a pretty niche problem compared to the every-ticket-of-every-big-show scalper problem. This affects <1% of ticket buyers. Scalpers currently affect 100%. Seems like a pretty reasonable trade-off.

Also, solvable. Everyone needs an ID that matches ticket or to be accompanied by someone with an ID that matches a ticket purchased in the same transaction (cap number of non-ID tickets per ID ticket, don't let people appearing over 30 in on a non-ID ticket). Then, when buying tickets, allow specifying a named alternate for each ID ticket in case the person can't make it.