Steam starts “launch.exe” which is the EAC launcher, that once it loads launches the VRChat.exe from itself. I don’t know if it’s possible to run without steam…
Running the VRChat.exe by itself only supports loading local worlds you’ve made via some option on the command line, and will be inaccessible to anyone else because it won’t be run from vrchat servers. Without any options it will do exactly as you saw, because it doesn’t know the local world to load.