idea is simple, i personally use duck duck go with brave instead of brave search as i liked it more
brave extension system is great already through which we could add additional features
rather than making a replica of every service brave should give placeholders on its website for customizability anyone can then choose which service provider it should choose, example a placeholder for search engine, a placeholder for email provider or for web id, a placeholder for vpn, a placeholder for wallet, a place holder code editor/ide, a place holder for online arbitration service such as kleros or any other policy related service, an utility token service and etc.
collaboration is better than competition in my opinion if we truly want the world to move forward it will be more realistic/a smart move to partner with each other, not only will it give the users the best features of each type of service, but also promote decentralization,
as for funding for each service i think a special utility token be made for funding the services as seen fit for making a business model for good which can then be used for funding. is there is a better way then use that but just make a system that incentivizes collaboration with each other, this can also include organizational interoperability at different levels.