Web of trust is rudimentary, something closer to pagerank is needed and that would rely on up/down votes which also need to be signed

What would be closer to pagerank?

Freenet ranks others by their distance to you and weights their votes from that before aggregating them.

And the up- and down-votes in the Web of trust are signed, because that is what happens automatically if you upload something under your key in Freenet.

Raph Levien implemented an attack-resistant trust-metric that had some formal similarities to PageRank for Advogato, a free-software developer community which failed: it turned out it needed some moderation even with this mechanism, and it didn't get enough. But the ideas and experience might be useful.

https://en.wikipedia.org/wiki/Advogato

This sounds like it tries to establish the notion of global respectability (see https://web.archive.org/web/20170628190710/http://www.advoga...). It’s something that I consider futile — part of the huge failure of clearnet moderation: To moderate billions of people, you have to give up on the notion of a global notion of who is always right.

It might be possible to establish for a given not heavily contested fact whether it is correct, but not to establish for a given person whether they are a crank. Just ask people around the world about the POTUS.

Freenet replaces that by personal trust. The only remainder of a global trust is initial visibility via seed-IDs. And that is transparent and can be revoked by every user.