Most people are good
If you spend a working life with that as your default assumption, you will be right more often than you are wrong, and the people you are wrong about will reveal themselves quickly.
An essay by Dustin Michael Drozd
The opposite default — assuming most people are looking to take advantage — is exhausting and self-defeating. It poisons every first meeting, every estimate, every handshake.
It is also empirically wrong. The vast majority of homeowners, vendors, employees, neighbors, and strangers are trying their best inside circumstances you do not fully see.
Operating from that assumption does not make you naive. It makes you efficient. You stop spending energy defending against ghosts. You free that energy for the actual work.
The handful of people who exploit the default reveal themselves within a few interactions. You revise the relationship, not the worldview.