My take is they didn't optimize for something that a small percentage of users would have problems with.
E: DS4 = DualShock 4, DS5 = DualSense; these are the standard PlayStation controllers for the PS4 and the PS5 respectively.
A good number of users will never hit troubles with their battery since electronic devices are treated rather cavalierly and replaced before those defects will surface, so I object to the wording that all users will hit that - but I still think it's clearly in the best interests of the majority of consumers to bargain for better lifetime extension support.