I think the feasibility of market dominance by streaming is a long ways off. Perhaps in Europe and parts of Asia it could be done with no problem, but in the Americas, Australia, and many other parts of the world where there is low population density and low incentive for ISPs to provide fast, reliable service, I don’t think it’s remotely feasible. Game devs would just be cutting off too much of their potential market. My previous home had speeds that averaged 1.5 Mbps or less; sually the speed didn’t exceed 0.5 Mbps in times of high activity and it had constant connection issues. And this is pretty standard in a lot of rural areas of the country.