Remember, Tolkien was an Englishman of a certain era, social roles/beliefs are also baked into the story too. Sam literally could have carried the ring, but for various thematic and societal reasons he only would have if Frodo literally couldn't anymore

Hobbits are the least dangerous ring bearers because their hearts don't crave power in the ways of men, and they don't wield it like elves. Frodo took on the direct burden because of his innocence and Sam would have picked it up out of duty to Frodo.

Strictly speaking he could have, but the ring doesn't stop corrupting you because it's a few feet away. Having people trade off the most direct effects while still getting secondary stacks all the time just means everyone falls under the effects more quickly from closer exposure being spread.

They don't want NONE!!!!