Incidentally, Remix is an open source project started by the React Router devs to create more framework features around React Router. React Router is probably one of the most widely deployed JavaScript libraries ever and is the furthest thing imaginable from a project created by grifters to sell online courses.
Remix was also a company that raised a $3 million seed round and then was acquired by Shopify (for presumably much more than $3 million). Shopify appears to continue to invest heavily in Remix and React Router development, and appears to use Remix heavily.