I'm really thinking of the pop aspect, so both narrower than the other influential artists you note, but also broader too.
Classical music (or jazz too as we know it) is different from pop the same way Elizabethan drama was different than the types that preceded it. The stage became the realm of the people in a different way than it had been prior. Elizabethan drama was "pop" compared to morality plays, or masques or the Italian traveling troupes -- there was "high" and there was "low", and little in between, and little political, unless it was fawning. Obviously, there were plenty of exceptions, and outside influences, but I think Shakespeare (in retrospect) changed all that. And his arc -- from comedy to tragedy -- matches the Beatles arc from love songs to more expansive topical songs.
While Sinatra and Elvis were critical (and James Brown), music was never central to (white) cultural change with the artists of the 50s the way Dylan and The Beatles made it -- it was a pleasurable post-war (in the Western world) adjunct but not a force for change or popular experimentation. Even more important, the Beatles were a BAND and not an "artist", I think -- they were a collective, a social construct -- which I think changed the direction of generations of musicians after in terms of how to present the art itself, and how the resulting art could be more than the sum of its parts (or one part). On a personal note, I suspect this is why I very much prefer "band" music to "solo artists".
Of course it's lovely that we have the recordings we have so that they can/will/could last in the ears of everyone in the future as opposed to just the lyrics and notes.
Anyhow, I really liked the points you made about The Beatles changing the game for everyone, and I guess we won't be around long enough to see if we're right. But, hey how long have basic rock drum patterns been around? Decades already! I think The Beatles are gonna last personally.
