"There is SO much that would have to be worked on that it would just make more sense to make a whole new game with better tech." That's the point.
FF14, much like PSO2, is too big of a fanbase to throw away or hope migrates to a new MMO. This is why many people saw what Sega are doing with PSO2:NG as an option for FF14 seeing as NG is basically "PSO3" in all but name. If they've BEEN struggling this much with the limitations they have then taking a NG approach to the future makes sense if they want to keep this game going for 10 more years. Even the devs have in recent years been very open about how the limitations of the game as is has been effecting them which is pretty damn strange for a dev to do.
And part of why PSO2 is getting NG is because the devs know their game looked old/ outdated and wanted to make it meet current standards for it's Western release. That's what I mean by "Western push".
At the end of the day we shall see. The Main take away though is that YP wants to drive this bus for another decade and I don't think they will allow fans of these genders to be left wanting for 10 more years.