Outputs generated by a called workflow can't be accessed by the caller workflow?

Just double checking this as it seems like a major missing feature. (New jenkins transplant so still figuring this all out)

Is this really still lthe case?

Outputs generated by a called workflow can’t be accessed by the caller workflow

Am I misunderstanding what that means, or does it really mean that I can’t have the equivalent of a jenkins groovy method that generates some data in a common way that I can share between other workflows?

ie: Yes, you can write functions, they just can’t have a return value?
I must be reading that wrong.

Assuming that is actually the case, is there some other mechanism that is currently being used to propagate data back from called workflows?
Perhaps passing in a filename and reading the data out of it from the caller?

thanks in advance