The only main character in Friends who got a spinoff series was Joey (Matt LeBlanc), and though it gave his story a proper ending, one forgotten detail in the main series completely changes it. Throughout its 10 seasons, Friends showed the audience the many struggles of Joey, Monica (Courteney Cox), Chandler (Matthew Perry), Phoebe (Lisa Kudrow), Rachel (Jennifer Aniston), and Ross (David Schwimmer) in all areas of their lives, with a special focus on their love lives. In that regard, Joey stood out as he hardly ever committed to a relationship.
https://screenrant.com/friends-joey-forgotten-detail-job-children-change/