Trivial content should not be given access to the highest tier rewards.
This is not a participation trophy. You should not be given 1st place prizes just for turning up. You want the Myth loot, you need to do something that earns it. Delve content is not it.
I find it interesting that nobody who is championing Myth gear from Delves doesn’t suggest that ?? gives Mythic gear. I would actually support that. And some other’s who would fight the first suggestion would probably also aquiese to the second. But strangely enough, nobody is putting it forward. Why? Possibly because that would mean Solo people would actually have to WORK for ti.