When I visit a user page with JS disabled I see three links "talk", "contributions" and "uploads"
When I click talk link, I see this page with the menu gone:
This breaks navigation flow as now there is no obvious way to get back to the user page. This is particular a problem if you land on the user's talk page and want to get to the user's associated page. Likewise, if I go to uploads, I can't easily get back to the user page. On mobile the only way to do this is manually inserting the URI or searching... not a great experience.