In the past few years I have been building up good reputation at various stores both online and offline. It bothers me I cannot use that reputation. For example a major supermarket chain here in The Netherlands rolled out self scanning from 2006[1]. They do random checks at the checkout, and for many years now they know I never forget to scan something. This resulted in the amount of random checks going down for me. That should mean something, and I should be able to use this trust/karma elsewhere. All these companies building data on me, and I can't use it myself.
The challenge is getting the companies to (from their perspective) "share" the trust information with the world, which includes their competitors.
I suspect we might need a "taxonomy of trust" so to speak, that allows the trust data to be anonymized and aggregated into commonly-accepted meanings of trust contexts, trust roles, trust relationships, etc. That might let these companies to release the trust data into such a format through a blockchain perhaps, and be able to participate in consuming the aggregated data. I'd need someone well-versed in game theory to figure out if an advantage is conferred to "leeches"; a company in such a scenario who only consumes the aggregated data but never send into the blockchain what they accumulate on their own customers. I think that's a real danger with such a scheme, but am not sure how to strongly dissuade that behavior.
Well, watch out. That sounds great if you trust everyone you interact with to give you good reputation. But pretty quickly that can lead to the recent stories about the Chinese social credit (assuming the stories are true). It can become a very subtle and powerful way to control people. Not to mention a legal minefield. Just look at credit ratings.
[1] https://www.youtube.com/watch?v=orjo0uNZFsk