Bicycles don’t even need drive throughs! The whole reason why cars “need” them is because they are huge and thus parking lots are huge and thus the walk from the car to the restaurant is inconvenient. Parking lots are roughly 16x as large per vehicles as a simple bicycle parking design. Which mean your average trip from the vehicle to the entrance is gonna four times as far than if the whole place was dedicated for bikes. with more advanced designs like two layer racks this ratio would grow even more.

On top of that, a place that’s catering to bicycle traffic would inherently be set up on a more human scale and aim to serve fewer people, thus the space needed for customer vehicles would be even smaller. So you’re likely be able to more or less park directly in front of the business anyway and just walk in, grab your takeout and hop back onto your bike at roughly the same effort as waiting in the drive through would be.

The real problem in this isn’t the lack of bike-throughs but the limited number or restaurants that a reasonable number of people could bike without risking their lives.