Duckduckgo is backed by microsoft/bing which they have a contract with.
Startpage is the duckduck alternative that uses google, its unknown wether they have a contract.
These places are still better then google/bing themselves but people often wrongfully assume that they provide a privacy oriented service.
If you really want to go anticorporate you can host your own searxng, which still by default uses results from google and bing but can be configured to use any on your preference and its code open to verify that they do not give exclusive permission to certain paying corporations.
Using searxng it can happen that some google result could not be retrieved because of api limits… one has to wonder why Startpage does not have those limits.