It's a mixed bag, but those fees from Google have been the primary source of revenue and supported the Mozilla Foundation for a some time. Ultimately I think the Mozilla Foundation is in a better position with those revenues then without.
Today, the majority of Mozilla Corporation revenue is generated from global browser search partnerships, including the deal negotiated with Google in 2017 following Mozilla’s termination of its search agreement with Yahoo/Oath which required ongoing payments to Mozilla that remain the subject of litigation.
