Isn’t the photo ID just because it’s no under 18s allowed? I doubt very much it’s to check the name and ID on the ticket.
The email says:
Ticket Holders must be aged 18 or over to attend On The Beach 2022. Challenge 25 is in operation at the festival.
Ticket Holders will be asked to show ID by security at the event gate. If you cannot produce ID, you will be refused entry to the festival.
Acceptable forms of ID are as follows:
Valid Passport
Valid Driver’s license
Valid PASS Card
I guess it can be used for checking age but it’s also used as a way of reducing/preventing touting for hot tickets like the event tonight. Promoter will ask for names at time of purchase which go on the ticket and the name must match the ID. Given the tickets do indeed have the OP’s name on them I’m guessing ID is more an anti-touting procedure. OP mentioned they only released the tickets 24 hours before the event; another procedure.