Frodo is not worthless and boring! He is just a more complex character. I really like Frodo's role in the books he's there to be a force of will and to keep striving for the impossible. Yes a massive part of that goes to Sam and of course he could not have done it without him. All of the characters were necessary but Frodo is equally responsible for what they achieved he was fighting a losing battle from the moment he put the ring on, he's also nowhere near as useless in the books as the movies make him out to be.
Which is one of my few gripes about Peter Jackson's version. Frodo is kind but realistic and solemn, the chances of actually doing what he sets out to are almost impossible. He also shows mercy and feels pity for Gollum understanding his suffering because Frodo too feels the weight and pull of the ring.
Of course Sam grows throughout the books as do the other two, but I feel people under estimate what Frodo is capable of and assume he is the weaker and more useless one out of them.
When Frodo is the one with THE responsibility, no one else has to go all the way to the end and into Mordor only him. Of course they all would have willingly, but he's the one who knows even if the others turn back or fall he has to keep going.
Because everyone's future is riding on him and the fellowship succeeding. Also Frodo didn't want trouble, or to go looking for adventure he never cared for any of that he just wanted to live with the people around him and be happy. Bilbo inadvertently thrusts trouble on his shoulders and marches out the door. Of course he didn't know the ring was evil and it wasn't his fault but it is the reality.
But still Frodo willingly takes up the ring in Rivendell knowing full well he could fail and fall under it's influence at any point during that journey, that he might idie and the entire world could be destroyed, He is just as self sacrificing as any of the others fighting their battles and it taking a toll on them.
Simply Frodo's is not just a physical battle but a mental one, he is utterly spent by the end. Still he makes that choice and risks everything in order to see good win out in the end and the world remain free. Frodo is just as much a hero as anyone else in the books.
And yes Frodo is steadily corrupted by the rings influence but so is everyone that touches or goes near it, thats the whole point the ring is heavy both physically and mentally the fact he made it to mount doom itself before finally falling under its complete influence speaks volumes about Frodo's will and strength, he can't even climb the mountain himself at the end he's so physically and mentally drained. Frodo is one of my favourite characters for his immense struggle throughout the books and his struggle over the ring and its corruption was just amazing.