Adding ID checks would make venue entry a slower and more tedious process.
Airports seem to handle them just fine?
That's the security check, of which id check is only one part. The bottleneck is everyone needing to take out their laptops and then repack their bags. Same with boarding. The bottleneck there is people putting their luggage into the overhead compartments.
Edit guess that doesn’t work for kids. Start the tickets at 10k and drop them by a percentage a day. Automatic price discovery. Rich people can just buy them whenever they want.