I can see this going to a tangent

Note here that most players don't use the ilvl requirements devs give, they only use it as a guideline. Players themselves find the bare minimum requirement for content through trial and error. i70 people going to -> BCB i90. 20 levels. You don't see them waiting to get full Myth gear THEN going there do you? They try.

It differs for every different encounter as well, Titan HM may have a lower or higher requirement. But basing from past clears/experience, no you don't need DL to do it.

Yes, upto a point, gear matters. But even then, (not flaming you) what exactly were you looking for in posting this thread? But in what I've just read, you want everyone to gear up, overgear it and faceroll it for free relics.