I think it depends on the context. Calling me a full stack is an acknowledgement that I can work on every step of the system and usually every part of the system. I don’t consider it to mean equally good.
However if it keeps getting brought up when I am not supposed to be working on those other steps, that signals to me that maybe they are trying to push more work into me that I shouldn’t be do.
I can appreciate that when someone says “Our X Expert”. It definitely feels like more praise and more value.