In my opinion, 99% of everyone worries far too much about the road trip use case and completely overlooks that most people will do almost all of their charging at home.
The big exception is Electrify America, which has about 600 sites now. Its good enough for many right now, though it isn't as deep or reliable as the Tesla Supercharger network.
Tesla supercharger coverage is pretty good with just over 1000 sites. EA coverage is actually pretty good too with just 600 sites. The # of sites needed for L3 in the short term isn't really that high. The number of plugs is important. I think EA averages 6 plugs per site, and Tesla is a little over 8 per site, with most new sites being 8 stall setups.
I would like to see Tesla transition to CCS in the US but that's going to be a hard sell without legislation.
The only comparable network to Tesla is EA and they hope to be about 3/4s the size of Tesla's network by early 2022.