It is sort of an assumption that people will act the way you think they would when they are away from you. We know how important it is to keep trust in the workplace, business deals that cost the company millions must be kept in secret and the ones with the right information could gain from it personally if they so choose to. An organization without trust will not run, you might get fired for a simple reason of your colleague backstabbing you on their own fault. Then a supervisor that doesn’t trust you will keep checking up on your every move, to correct whatever mistakes and oversights you left.
There is so much done to make sure that “trust” exists. We have business contracts just so the other party will not turn back on their dealings. We incentives people with higher pay the more sensitive information they are dealing with. Then records of transactions are kept just so there is proof to prevent that random false claim dispute. Basically, productivity and the economy suffer from that lack of trust. Imagine how much a company can achieve if only there is none of those necessary administrative work and operate on trust.