Why doesn't “set -P” work after a pipe?

Question

C:\\>type c:\\output.txt
abcd
C:\\>type c:\\output.txt | set /p V1=

C:\\>set
... A bunch of junk, NOT seeing \"V1\"

What happened? According

Answer 1

The pipe seems to create a new CMD instance to carry out the next command that is receiving the pipe data. So when the pipe has concluded, that CMD instance exits and the variable is lost.