I called ahead to have taxis pick me up for early morning rides to the airport, and they were always early and helped me with my bags. I took taxis over to the Boston College area when I was taking music lessons at a studio there. I took taxis home from sports events and concerts near Fenway. Even when coming out of a crowded show at House of Blues, it was a short wait for taxis.
I never once experienced a broken credit card machine. I once did ask a driver if they accepted credit cards, he said no, and I waited about 30 seconds for the next taxi to come by -- on a side street on the Somerville side of Porter Sq, so not even close to usual taxi spots.
Getting taxis in Boston is cheap, safe, and reliable, with pretty short wait times, easy to deal with dispatchers, drivers who show up on time, cars that are clean and 99.999% of the time have functioning credit card machines.
I honestly don't know what on earth you're talking about.
None of this is an argument against Uber anyway, because people use Uber for features that even good taxis don't have, including price reduction, better real-time tracking, an app interface, and other things. And Uber drivers certainly can do things worse than taxis -- such as simply fail to show up, treat you rudely during the ride, or try to make you exit the car in an inconvenient/unsafe spot of the street at your destination. Uber is not intrinsically better about this kind of thing than taxis.
But some things you absolutely cannot say, at least about taxis in the Boston area, are that they are anything but clean, safe, reliable, punctual, and able to take your credit card.