the chargers aren’t standard. Each charging site has different plugs, apps you have to download, etc

– US has 2.5 common plugs. An old one that’s mostly gone, the standard one, and Tesla. However Tesla opened theirs as a standard, and it looks like they will be de facto standard across the US

– The protocols are compatible. The adapter for my Tesla to use the other standards is mostly plastic and dumb. You just need something to fit a different socket

– yes, the state of apps sucks. Everyone wants to maximize their profit. However I thought most non-Tesla chargers had a credit card reader, so as long as you can find it and it works, you can use it without an app. Tesla is another story, but does seem t add a lot of convenience with their app