I was thinking about some features that are already lowkey implemented in telepresence software, like AI-assisted direction e.g. when I bend over the table to point at a token, the viewport knows where I'm pointing and puts it in focus. Or features AR-like features where we can look at the same virtual magic item and turn it around for each other's inspection or push the 'battle mat' towards another player. Stuff that exists conceptually but is not commonplace in consumer tech just yet.
But you're posing a really hard question - I already said in my first post that I don't know what the new design paragdigm would look like. Again, I just have a hunch that current state of the art is far from ideal and if it improves dramatically, it might give the hobby a whole new leash of life.
EDIT: It's funny you bring up the rules system though... one thing I have learned this year is that the current rulesets involve a lot of waiting around for other players to take their turns. Not a big deal off-line but online it can sometimes be hard to keep everyone's attention focused. I could see clever designers coming up with ways to have players 'out of the spotlight' (in RP or combat turns) more engaged. But here too, I'm not smart enough to see the solution... just chafing at the limitation of our current systems and tech.