I definitely see where you're coming from here, and I didn't put it that way to insult you in any fashion, but to emphasize that my problem with them is in their historical rootlessness -- how irregular they are relative to the historical standard as developed at a given place or among a given people (as opposed to being modifications of something that is still well-rooted in itself; cf. the Liturgy of St. Cyril being an 'Egyptianized' version of the Greek Liturgy of St. Mark). If everything is a liturgy just because people are gathering together to do it in service/praise/supplication of the Lord, then certainly that would be a good argument, but I don't think you can use the understanding of the word itself to build such an argument.
For one thing, it appears that the "liturgy" as a "work of the people" in Ancient Greece and Rome was something that was assigned to particular benefactors by the state, such that if you didn't what they asked of you how they they asked you to do it, you wouldn't be performing a liturgy at all:
"In ancient Greece, particularly at Athens, a form of personal service to the state which citizens possessing property to a certain amount were bound, when called upon, to perform at their own cost. These liturgies were
ordinary, including the presentation of dramatic performances, musical and poetic contests, etc., the celebration of some festivals, and other public functions entailing expense upon the incumbent; or
extraordinary, as the fitting out of a trireme In case of war."
(
source)
So let's say you're called to service in an extraordinary liturgical capacity. If you show up to the trireme (one of those ancient Greco-Roman warships with the three rows of oars) not with the men and supplies needed to outfit the expedition, but with the lute and the dramatic masks and costumes necessary for an ordinary liturgy consisting of a musical and theatrical performance, have you performed your liturgy? No. You may be doing something else to some other, related end, but it would not be that which was
established for you by those in charge of telling you what you need to do and how you need to do it.
Similarly I don't think it's up to any one of us to only perform things up to the degree that we wish to, or in this particular style that we prefer. Liturgies of course do develop over time,
we should hope organically, but again, change via adaptation isn't the problem. It's just kind of hard to see how this
is in any sense an organic adaptation of this
and yet I doubt that the people in the first video had gathered to do anything other than to praise God!