When they get clearance to drop people off at the main terminals, that will be more convenient. Pickup at the terminals is harder. There will be a need for a staging area somewhere in the parking structures.
Few major airports have Waymo at all. Phoenix has allowed pick-up at the airport for ages. (EDIT: Never mind.)
Waymo at airports could work really well with automatic dispatching. They already have an app running in the customer's phone. It should be aware of when someone with a reservation gets off an airplane, and how close they're getting to the pickup point. With good coordination, as the customer heads to the arrival lanes, a Waymo pulls out of short-term parking and heads for the meeting point.
A few more years, and humanoid robots will put the luggage in the trunk.