Consider

ping -c 4 ya.ru | grep 64

Run it in PS and in bash. Compare UX.
In PS output of ping is collected, then it's passed down the pipe all together.
In bash you see output of grep instantly after ping send one line to the pipe.

As @BrucePay pointed out it never appeared to be a problem on windows due to the lack of pipeable native command-line tools.

As a minimum, we should sort out this buffering flow.
Desirable: improve pipe speed for certain cases (i.e. native command to native command).

Open question: can we use a native pipe to provide a compatible speed, when pipeline doesn't involve PS commands?