AC is typically used for power grids because it’s very easy to change voltage with a transformer. You can have 100-200V in households, and use a cheap transformer to step up the voltage to 100+kV to reduce resistive losses for long distances.

AC works well, but there are technically some downsides with AC, like the skin effect and parasitic capacitance. With modern technology, it’s pretty easy to step up/down DC voltage, and by using it for the biggest, longest power lines, you see some nice power savings for the effort. It’s called “HVDC”.