I'm wondering why this is the case.
Why does it cost more to get a ride if you reserve in advance?
The Guru Take
There are no fees for reserving in advance. At least for Uber and Lyft but...
There are no fees for scheduling Uber and Lyft rides in advance. By default, the fares are supposed to be the same, as "scheduling" a ride essentially just schedules the outbound requests to the drivers to a time you specify. The fares are supposed to be calculated the same as any other ride.
With that said, Uber and Lyft have different policies on handling the potential surge pricing that may be applied to the trip.
Uber fare on Scheduled Rides: Uber will display the regular fare at the time of scheduling the ride. This may be a standard estimate or an upfront pricing. However, when the time of the ride comes, if there is a surge for the trip you are about to take, the surge will be applied. Uber allows you to schedule up to 30 days in advance.
Lyft fare on Scheduled Rides: When scheduling a ride with Lyft, Lyft will attempt to estimate the potential surge and display the fare that incorporates the increased fare. So, Lyft basically quotes you a fare and guarantees the fare at the time of the scheduling.
If you saw an increased fare for when you were about to schedule or "reserve" a ride, you may have been using Lyft.