Why would Frodo and Bilbo leaving other hobbits behind especially after destroying the Ring at the end of the movie?
The reason why Frodo left Middle earth, his ancestral home was that he needed time to rest and heal. The fighting with the Lord of Rings left him injured, though Frodo endured the course of Lord of the Rings and won he sustained injuries.
At the end of Return of the King Frodo chose to make the journey to the legendary realm known as the Undying Lands, unlike the other hobbit who remained at Middle earth. This is how Frodo’s journey finally ends; they board a ship from Grey Havens since they are no more needed because men had come.
Undying lands is a special place away from Middle-earth which is only welcome to immortals and Ring-bearers. Frodo and Bilbo journey is headed there but many people wonder they didn’t stick around at Shire with the other hobbits.
Since the pain of having going it all over again was inevitable each year Frodo sought for a place to go to escape the pains of his wounds which pain had to return afresh and hound him each year. Frodo and Bilbo could not escape the burden the ring had placed on them at Middle-earth .