I believe you've identified much of the problem: the way people typically share knowledge is not how the internet is built. It was captured early by marketing

I believe you've identified much of the problem: the way people typically share knowledge is not how the internet is built. It was captured early by marketing and introverted engineers. If instead we give people a couple simple tools, decentralization will happen naturally and facts can surface through a natural web of trust. Just like in the real world. Part of this is letting go of the interface. Right now our interfaces are riddled with dark patterns and fall far short of accessibility. We should own our interfaces to knowledge, since technology is a lever that is an extension of ourselves. If we focus on knowledge, advertisements and spam naturally fall away. I'm not sure pure push would work, I think a sync+hash model is better: this is what Urbit and IPFS figured out early. But the interface to that is currently horrid for any average person.