Howard!
There’s far too much Marvel comic book content for the MCU to give every franchise character a movie. With such limited time (and maybe interest, too), the MCU is going to have to pick and choose which heroes get movies. It is a business, after all.
But that doesn’t mean they won’t reference lesser-known characters from the comics. For instance, did you know that Howard the Duck makes an appearance in GOTG? Granted, his cameo is brief during the end credits, but keen-eyed viewers also spotted the anthropomorphic duck in the second film, too. Is this foreshadowing for his own film franchise? Analysts say, “no.”