"Why should production in the Permian fall more slowly from the peak than it has in the Bakken, where production has fallen 33% in four years?

The short answer is there is much more recoverable oil and gas, by far, in the Permian than there is in the Bakken:

(Picture Warren and Charlie salivating)

Permian (Delaware and Midland Basins): 70.5 Billion barrels of oil and 300 Trillion cubic feet of gas.
Bakken: 4.3 Billion barrels of oil and 5 Trillion cubic feet of gas.

U.S. Geological Survey assessed undiscovered, technically recoverable continuous mean resources:

46.3 billion barrels of oil and 281 trillion cubic feet of gas in the Wolfcamp shale and Bone Spring Formation of the Delaware Basin in the Permian Basin Province, southeast New Mexico and west Texas.
pubs.usgs.gov: PDF document

20 billion barrels of oil and 16 trillion cubic feet of gas in the Wolfcamp shale in the Midland Basin part of the Permian Basin Province, Texas.
pubs.usgs.gov: PDF document

4.2 billion barrels of oil and 3.1 trillion cubic feet of gas in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas.
pubs.usgs.gov: PDF document

Bakken and Three Forks Formations in the Williston Basin of Montana and North Dakota. The estimate includes 4.3 billion barrels of unconventional oil and 4.9 trillion cubic feet of unconventional natural gas in the two formations.
usgs.gov - Usgs releases oil and gas assessment bakken and three forks formations

I'd argue that the Bakken is more fully developed with over 11,000 wells drilled since 2013.
gis.dmr.nd.gov: ArcGIS Web Application

Bakken production peaked in October 2019 at 1.46 million barrels a day, then dropped precipitously during Covid as rig activity dropped to almost zero as wells were shut-in due to lock down and travel restrictions? North Dakota's Department of Mineral Resources indicates Baker production was up to 1.11 Million barrels per day as of February 2023. That represents a drop of ~24% from the peak.
dmr.nd.gov: PDF document

With rig activity ramping up again post Covid, the Bakken production decline has flattened considerably. If the oil price climbed and remained above $100/bbl for a considerable time, rig activity would pick up and, Bakken production would likely increase again.
eia.gov: PDF document