At this point, why don't the companies who run Chrome derivatives work together to build a fork that evolves separately from Chrome? Edge, Vivaldi, Opera, etc. will never get the marketshare on their own to rival Chrome, but together, they could make a dent with a unified browser engine.
Gecko (Firefox engine) already is worked on, why not contribute there instead of losing community? If anything why those browsers use engine that is controlled by a single company?