How? Fork the engine or whole thing? How to pay for it? Costs many $$$ to build. Would maybe cost less without the stupid things they do but...seems a difficult calculation to make.
There are dozens of smaller browsers that don't abuse their users. When Firefox loses the mind share it no longer deserves they will finally get enough money to hire a full-time developer.
Which all use chromium, which is in practice no different to using chrome in regards to extending google's web dominance?