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.
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.