Inculturation is a difficult matter but not only is there nothing wrong with it but it’s desirable in some cases (I’m thinking of Fr Matteo Ricci in China).

As long as the new rites have the same orthodoxy, objectivity and Godwardness as the old ones.

That said, that and the Tridentine Mass and Roman Breviary (the ‘base’ for all Western liturgies for the past 425 years and before that this was true of older forms of the Roman Rite) are not mutually exclusive. Big swaths of Western Europe, the Americas and the Antipodes should be using the old Roman Rite! It’s theirs. (English speakers can use the existing translations into liturgical English like the Knott Missal, American Missal and Anglican Breviary.) And that’s still possible, unlike trying to revive Sarum or the Gallican Rite, because it’s still in living people’s memory.

I know of no massive movement in the Eastern churches to scrap or augment the Byzantine and other traditional rites.

The last priest celebrating the last Mass or reading the last office in a shattering universe may well be reading in Latin or Slavonic… or using a rite we’ve never heard of because it doesn’t exist yet!