Streaming happens. It has to happen, if everyone's needs are to be met. The problem with streaming is that it limits the possibilities for the future of the child. If a mechanism for switching between streams existed and was easy to use and effective, there would be no issues with streaming.

Actually, there would still be one issue - the self-esteem one. How do you convince a kid that they're capable and intelligent when the other kids of their grade are doing harder work than them and they know it?