Harry Potter adapted the books. The MCU adapts comic book stories all the time. LotR had to adapt. Drizzt or any other known Forgotten Realms book/character would need to be adapted to the screen. It's exactly the same.
But it's really not the same. Harry Potter was an obvious thing to make, the books were overly popular. J. K. Rowling was the first author to become a millionaire through a book series. The movies were an obvious step on the path of developing the story. The movies started coming out while the series was being completed.
LotR has long had a fanbase as well. It was another obvious thing to adapt to a movie.
The MCU routinely makes huge changes to comic book plots. They aren't the same stories.
Drizzt isn't super well known. It is not an obvious story to develop into a movie. The people who read the books would probably not care much for a direct translation from book series into movie series.
They're not going to remake a pre-made D&D adventure or FR book. That's not the thing most people would watch, IMHO. People who see a D&D movie coming out in theaters might be intrigued and see it, but if it's called something like, "Drizzt Do'Urden and the Crystal Shard" they would probably never go see it.