It's just my opinion of course, but I don't feel that ANY "worm" is viable as an ONLY staple feeder.
None of the worm types let you gutload them the way you can with Dubia and Crickets, so I think
that any of the worms would be lacking in some nutritional values, and that makes them invalid
as an only staple feeder, even Phoenix Worms.
A a staple along with other varieties of worms, sure...variety can help cover any gaps.
As supplemental feeders along with properly gutloaded Dubia/Crickets, absolutely.
By themselves and only themselves, no.
IMO at least.