Tipping culture in Bellevue?

For context, I have lived in Seattle most of my life with a four year stint in Spokane. I am an Uber Eats and Doordash driver, and last night on a whim I did a dinner shift in Bellevue (I live in Seattle). I did ten orders total. One was to a shabby apartment, and the other nine were to houses obviously owned by wealthy people. I received one tip for the whole night, and it was from the delivery to the shabby apartment. It was bizarre.

Other deliver/service workers working in Bellevue: Do you experience the same thing? That the wealthy are less likely to tip than the average joe? Everyone in Seattle and Spokane tips regardless of wealth so it’s just not adding up. Can any of my east side people provide some insight?