Yes, PS and DS are beloved by us Gen Xers, but they are really beloved.
Gen X here, as are most of my group, but I know I'm not the only one who finds both a bit meh. They might be beloved by you and your group, but that's by no means indicative of that level of fandom in everyone.
We play tested the mystic. And the same problems kept cropping up. It was stronger than everyone else, it did everyone else’s stuff, often better.
This could happen! Amonkhet MtG.
https://i.*****.com/XHIc4oH.jpg
Furthermore, the reason they don't have a "growing fan-base" could be because there is no new material.
Kara-Tur doesn't have to be a PR disaster. I'm not sure how D&D is doing in Japan, South Korea, and China, but if there is a market, it could be designed there as the first "international D&D book."
Gen X here, as are most of my group, but I know I'm not the only one who finds both a bit meh. They might be beloved by you and your group, but that's by no means indicative of that level of fandom in everyone.
We play tested the mystic. And the same problems kept cropping up. It was stronger than everyone else, it did everyone else’s stuff, often better.
Like Arts and Arcana. Instead of art it will rules. Rules everywhere.I am most curious to see what they do for the 50th Anniversary.
I think it would be great if they could issue some commemorative reprints of old classics. That seems like low-hanging fruit.
But what will they do with 5e?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.