Alas, as much as some of us would like to forget Star Trek: Enterprise, pizza was referred to a number of times on that series, showing that it still existed between the present day and the 23rd century.Here's a crazy idea. Maybe pizza and beer were forgotten by the 23rd century, but Gillian reintroduced them when she traveled forward into the future, thereby creating a timeline in which pizza and beer were once again commonplace by the 24th century?
Kirk didn't just reintroduce whales to the future. He brought back pizza nights!

Kor