ELI5 why is every other charging Network so hit and miss except for Tesla?

There has to be some money in having a good charging Network. I'm looking to drive cross country in the USA and according to Plugshare it's pretty hit and miss except for Tesla. Why is this?

This is what is going to kill the electric car. I know everyone's switching over to NACS but will non-tesla NACS chargers be any more reliable? Should we have to depend on one monopolized auto manufacturer for all of our charging needs?

Also, people outside of the USA are your non Tesla networks fairly reliable?

Edit: It seems like all the non-usa people are saying their networks are reliable. What are we doing wrong here in the USA?