You are thinking of price discrimination, which is a subcategory of dynamic pricing. Changing prices based on time of day, current demand, tiers/SKUs or really anything else is also collectively dynamic pricing.
Price discrimination isn’t a subcategory of dynamic pricing. Dynamic pricing is equivalent to what is colloquially referred to as surge pricing, whereas price discrimination is based on the buyer’s perceived willingness and ability to pay.
Dynamic pricing could technically fall into the category of price discrimination if the discrimination is temporal (e.g. people who need a taxi at 8:00 AM pay more than people who need a taxi at 8:00 PM), but generally price discrimination refers to changes in price based upon anticipated demand, whereas dynamic pricing refers to changes in price based on actual demand.
I would probably call this "charge discrimination", which gives a clear indication which side of the party is empowered with this concept.
Still, wildly volatile pricing is also an excellent reason to avoid taxi apps. Why politicians have no desire to rein them in is baffling. I guess the stock market is really all that matters at the end of the day....
