It's no longer proprietary. As of last year the standard is open and anyone can adopt it without paying Tesla a dime.[1] Of course car manufacturers will have to negotiate access to Tesla's charging network, but that's also true of Electrify America. Considering the advantages of Tesla's connector (much more compact, much more popular than CCS in the US), I hope it wins. Now that Ford[2] and Aptera[3] are adopting it, I think it will.
1. https://www.tesla.com/blog/opening-north-american-charging-s...
2. https://media.ford.com/content/fordmedia/fna/us/en/news/2023...
3. https://aptera.us/tesla-charging/