So you're suggesting a Firestar movie would have killed because she was one of Spiderman's amazing friends? Ghost Rider is pretty well known (not MCU, but point stands) - terrible movies. IM was a great movie that used great source material. The comics are full of them. Its not just that they lacked FF, mutants, Namor, and Hulk and Spider-Man to a degree, its that they shitty movies and launched crappy products with the characters they did have. Both FF movies sucked and most of the X-Men movies sucked. Just now I saw a trailer for Echo, a side character from the Hawkeye tv show.... Thor Ragnarok was kinda great, but 2/4 were garbage and the other one wasn't great either. 2nd Dr Strange: bad. IM 2 and 3: Bad. BP1 and CM 1 were box office smashes; they were bad movies. Iron Fist, The Defenders, Vision & Scarlet Witch: Bad (they have an Agatha Harkness tv show coming out!).
Edit: and yes they def need to focus on the FF and Xmen, but its not going to be easy if they don't invest in them. I don't want to see an X-Men movie and then a tv show about Kitty Pryde's parents.