Porsche doesn't need one pedal driving. Porsches and many other EVs (e.g., BMW and Genesis) use a blended braking system. Under a blended braking system the initial depression of the brake pedal invokes regeneration. Only a hard pressure or a very fast pressure invokes the friction brake. Teslas and others (e.g., Lucids and Rivians) don't have blended braking systems. Stepping on the brake pedal immediately invokes the friction brake so Tesla initiated the one pedal system to gain the benefits of regeneration.
Drivers coming from a Tesla tend to want to be able to do one pedal driving. If they migrate to a vehicle with blended braking, they will have to see if they can get acclimated to it or just limit their purchases/leases to the models without blended braking.