For some websites the starting of the webpage with complex authentication and multiple redirects, w3m does not support. But like with curl package in case we can take the cookies from say firefox export cookies plugin and supply to w3m (with a new flag to take user supplied cookie file), I guess it can render the remaining webpages which are where we spend our time.
https://git.sr.ht/~rkta/w3m/commit/af467c3e7ec26a2720696054887d6caec6887b72 This allows passing a cookie file, but one still has to convert the curl cookies to w3m's format.