At this point I think it's safe to say Euphoria have been an abject failure. It's helped accelerate powercreep to an unprecedented level while also boxing character into more and more narrow roles, neutering team comp diversity. Rather than patching holes in characters kits and bringing them up to a modern standard Euphoria are being treated as a necessary part of the kit and they're being handed out to units who simply don't need them like Vila and Marcus.
Frankly I don't see any way of walking back from this now since it's become such a large expectation. Euphoria should have been restricted to 5* and below, or at least heavily scrutinized for the 6*s who really needed it, like Newbabel.