One's popularity on ML community isn't indicative of his/her research capability. Have you seen Lex's name on any of the most important papers recently? Probably not. Do you know Quoc Le? Maybe not. In this subreddit, Quoc Le's name is mentioned far less often than Lex's name is, but they are at totally different leagues as a researcher. This is understandable, since Lex has a bit of entertainer aspect. But this doesn't mean that Lex is not a good researcher. I don't know him as a researcher, but I guess he is good.

Do you know the first authors of Transformer paper or BERT paper? Maybe not. There are some great researchers whom the majority of the community is not aware of. The majority of the community is not capable of recognizing who the real deal is, but this is not necessarily their fault, as it is a highly non-trivial task anyway.