Oxycodone is more addictive than MDMA (not that I think that it should be illegal either, oxycodone should legal & regulated and available for purchase by adults IMO just as all drugs should, ideally)
That’s not to say that MDMA cannot be abused, but it’s more appealing to use oxycodone every day in a way that it isn’t with MDMA.
Also, regarding delta 8, that hasn’t been around long at all in the grand scheme of things but I honestly don’t see any “problem” developing there at all. If anything I’m amazed by how prevalent it got so quickly and how generally tolerated it is by the authorities…I wouldn’t say that it flew under the radar necessarily cuz it’s sold openly seemingly everywhere