Indeed! Don't expect anyone to do more than that online.

Giving other users a trust score on every category of trust isn't doable nor useful in the first place.

1. Humans suck at giving numerological ratings (because we don't know what it means, at aaaall). Best we can do is ordinally rank people which is an even more obvious UX nightmare.

2. Categories are not clear-cut, and therefor cannot be clear.

3. The cost is on the ones providing the information, instead of the ones who want to use it. You cannot gamify your way out of that.

4. How would you even interpret those ratings without algorithms, that could have solved the whole problem without even bothering the user?

And those are just the issues when these WoT ratings would be static, which they can't be. Maintaining them dynamically over time, lol, good luck.

In this case Big Tech might actually be inspiring. They don't bother you with asking Bob how much you he would score Alice on Trust in a relationship setting, they know he's in love with her before he does.

How? Just look at users actions.

Literally every event = an expression of Trust.

Let algorithms compete on recognizing the patterns in those actions and in being useful for specific applications. Some will be crude and basically free when that's good enough, others will be very advanced and pricey.

The data is public. This will happen anyway. Users can willingly share more data when and to whom they want.

How are you planning to compete with opt-in free market solutions that are built on the actions users are already doing?