Trust happens between you and another entity - whether it is an individual, an organization, or an institution. It’s hard to get above a certain number of these trust connections. You start needing to use proxies to evaluate how much you should trust another entity - either associations with an existing trust connection (they’re part of a trusted institution or someone on you trust trusts them Trust is transitive) or you use a measurement as a trust proxy - books published for expertise, net worth for a host of things, etc.
Institutions are a mechanism for scaling trust. However, I suspect that The mechanism by which we trust institutions is the same mechanism by which we trust people. So while institutional associations can enable you to trust a large number of people (see: the US military) the number of institutional trust connections you can create are limited.