What will end up happening is not that Amazon will have to compete with others on video game streaming for example, what will happen is that video game streaming will disappear because not viable.
Browsers won't suddenly flourish when Google cannot finance browsers anymore, they'll just turn to shit.
People won't spend $50 a month to subscribe to what Google currently provides for free, they will just lose access.
In the end the users will just flock to the Chinese equivalents which will be happy to steal all of the western data for the low cost of providing file hosting.