But as @twf rightly points out, Low Mass was not meant as the ideal,
More than that, it originated as an outright abuse . . . what became known as the “High Mass” was
the Mass before the abuses which eventually became normative, and were codified at Trent.
I’m not a liturgist, or even close, but I do understand that some “lost” practices were restored in the OF. And also that, along the way (I think with the rise of the Low Mass, but again, I’m not the one to ask) the distinction between the priest’s and congregations’s parts got lost, and some were assigned to the priest essentially “for good measure.”).
Given that the records were insufficient at the time to tell, I’m skeptical that we can know much more today, save perhaps from other rites.
I still recall my first Divine Liturgy (which was in English), and my awe at it as more a seamless whole than the OF, which seems to me to go from one part to another.
Tidbits:
–the first time my Byzantine priest served the liturgy with a deacon (at the other parish, not ours), he commented the “I was able to sit there like a potted plant” as the deacon did all the work



. . . . and when we had a deacon for a while, I was intrigued by the difference (and it made more work for us servers, as he keeps going in and out of the Holy Place :crazy_face
– Fr. Serge Kehler of blessed memory, a Ukrainian Catholic liturgist (who translated the Divine Liturgy into Irish and served it in Dublin!) commented that the difference between a liturgist and a terrorist is that sometimes, you can negotiate with a terrorist


:crazy_face

. (he was active on the
byzcath.org forums until a couple of years ago.)
You are assuming that the eastern liturgy is close to the liturgy in apostolic times, which isn’t necessarily true and needs an argument on its own.
A good point in its own right–and it is worth noting that part of Rome’s position in the early centuries was due to
Rome being the conservative church that was suspicious of change.
That said, the Liturgy of Addai and Mari is a second century liturgy, the liturgies of St. Basil and St. John Chrysotum were earlier and later fourth century, respectively, and the Liturgy of St. James is also fourth century, apparently a bit older than even Basil’s . . .
At that point, at least, the East changed slowly (St. Basil
shortened the liturgy to about three and a half hours, and Chysotum by another hour, or some such). The west, or at least Rome, historically destroyed the old liturgical books when new ones were promulgated.
Keep in mind, also, that before Trent, the liturgy of the Diocese of Rome was
far from universal in the west, although quite common, and that Latin was not universal, either . . .