xargs/etc are like arcane legos, where there's more than one brick vendor in the mix with different vendor's versions of the brick supporting different features, or the same feature but implemented in different ways. And even if you're only dealing with one brick vendor, there's still little uniformity in the interfaces of different bricks. GNU vs BSD xargs, -0 vs -print0, etc.

True lego have the property that if two parts snap together, it's a valid configuration. That's definitely not the case for unix utilities. You have to read a manual for each sort of brick.