New EV owner here. We charge at home so I don’t need to use them, but stores nearby have chargers. I tried them to see how they work. They are often broken.
One store has a Volta charger (free!). It worked great the first time; the next time I went it was broken.
Walmart has an Electrify America fast charger. The first time I went, 1 of 3 was not working. The next time I went, 1 of 3 was not working, but it was a different one.
Was I unlucky, or are these charging networks unreliable? Has it been getting better or worse over time?
You're not unlucky, in the U.S. any charger that isn't made by Tesla is unreliable. It's been getting worse over time, and the only real hope is that every manufacturer is switching to Tesla's charge port (now called NACS) and getting access to their Superchargers.
I had a non-Tesla EV and eventually got a Tesla because I need to road trip regularly and can't handle chargers being down.