Which is important because without any external reviews how would we know if it wasn't written by some people with "dangerous" skill levels being high enough to look good for someone having no idea about TLS but to low to actually get it right. I do have seen some open source projects over the years where that was the case and the authors where not open for any form of critique, which lead to situations where you seemed to get a high quality well maintained library but you got a somewhat high quality well maintained library with hidden extremely dangerous bugs the authors have no intention of fixing and closing all issues about them...
Nice to hear that Rustls is not such a bad apple but a most likely good pice of work.