Trust and psychological safety are not the same thing.
Trust occurs between individuals. An employee can trust a manager (or vice versa) because they have built a relationship over time. Trust is a key element of relationships between individuals.
Psychological safety occurs between multiple people. The only way to have psychological safety is when all members of the team feel safe with every other member. This is what makes psychological safety so difficult and fragile.
If a team has 5 members, but people don't feel safe with 2 of them, there is no safety in the entire group. People will hold back opinions and thoughts because of the two. It is akin to the old saying "a chain is only as strong as its weakest link". When you deal with multiple people and the exponential relationships that occur, it is easy to lose psychological safety. Once lost, it is hard to regain.
Trust - in a sense - is much easier because the parties are limited and can work in a small circle of influence. Psychological safety is much harder because of the variety of people and personalities in the group. It is why psychological safety must be a focus every minute of every day. Even the slightest blip can cause huge issues.