There a few ( not tiny, but not a lot ) of set bonuses that are so perfect that even though they top out early (25, 30, 40) they fit into high end builds naturally. Oftentimes a build is so overpowered missing out on “ basic enhancement upgrade” on a non primary power means zip.
Also, when doing an alt build for low level Ouro badging these “baby sets” come in handy. Since your enhancement values get squished so hard at 10/15/20 and even at 25 you are building for set bonuses and cramming Globals on.