taxies are not cheap. Just a weekly grocery run for a month is more then my monthly expenses in my paid for car (gas, maintenance, and insurance). A few more other trips and a car is cheaper. That is before we get into my last taxi was driven by a smoker, and a window was broke on the car. (uber might do better now, but as all uber critics note uber fares don't pay the driver a living wage after real expenses, and thus only work out if you have the car anyway)

It can work out, it depends. How often do you need to use the taxi to not inconvenience your lifestyle? Are you the type that would have a new car or used car? more expensive. Would you do your own car maintenance? Do you life to vacation in remote places where you would have to rent a car? Do you have kids (no taxi has a car seat). How good is the local transit service? Is parking "free" with wherever you live and go (use it or not)? I'm sure there is more.

Also if you only need a car for 10% of trips, renting might be cheaper than buying. I don’t own a pickup truck because I rarely need one, but when I do need one I rent one from Lowes or U-Haul.

That's exactly the point. There's a long tail where electric assist bikes and transit aren't ideal options, which is exactly the market where Cruise is trying to fit.

Personally, I did use ride shares, but there was enough need for me that the math worked out for personal ownership.