Hard forking doesn't solve the problem of closed source.
If the goal of a hard fork is "the community will invest equal resources that Google does today" then you wildly underestimate how many engineers work on Chrome.
but perhaps we dont need several gigabytes compressed code to have a browser. perhaps what google have been doing is an utter abomination?
But the open source project wouldn’t need to invest as much as Google does. There are all kinds of features and things they are working on that the general public really does not care about.