At TPE airport, we paid NT$1,000 for a month of unlimited 4G data on an eSim. It gave us a local number as well (some data sims don't) which is useful for signing up for some services such as Youbike.

They do shorter plans, and personally I don't think paying any extra for 5G is worth it.

https://prepaidsim.twgate.net/index_en.html

Credit cards are accepted but AmEx is always a tricky one. They charge higher fees to vendors so many places, including here in Europe, don't take it.

Uber app works but as has been said, just flag down a cab unless you need one somewhere quiet. Not that there are many quiet places.

Also, to repeat the above (and this is not unique to Taiwan) just get cash from a cash-machine. And always select the option to let your home (US) bank do the currency exchange, NEVER let the ATM do it. Same if using a credit card in a shop/restaurant/hotel. Sometimes the machine gives you the option to have the amount instantly exchanged. Don't do it. It's ALWAYS a rip off.