In my country, the most popular taxi app(yandex) has an option to allow hitchhikers. If you and other person order a ride with this option on and a similar route, it will pick one of you then the other, and then drop each other off. Currently, the savings are not as good as I would expect, roughly 15-20% off for both, and there are hard limits like 2 minute wait time with no paid waiting, non-refundable order fee, only one person, no baggage, and this option only shows up if you’re either taking a long ride or if someone’s already riding one that somewhat coincides with yours. Sometimes, no second is found and the company, but mostly the driver, just have to eat the discount they gave you for enabling it. But, already as is, taxis are wrecking public transit and car ownership by utilizing cheaper immigrant labor. With scale they can potentially be filled more consistently and with more than 2 riders, and with autonomous cars there’s no need to pay the driver, even further reducing the cost. Also, never parking could massively increase throughput on some of the streets where there are entire lanes are filled with parked cars. At least in my city, this has enormous potential. The only problem is that competition is lacking, therefore reduced cost won’t necessarily result in lower prices.