If you're a lapsed player - or simply a burned-out one like me - what would you like to see to get you excited?
I don't think that should be a primary design goal.
The problem with chasing lapsed players is that they have myriad reasons and a lot of them have little to do with 5e itself. The biggest one is that they got busy. This happened to me and almost all my gaming friends when we hit our 20s, started careers, families, etc. Gaming became a thing you did on occasion and the time investment of RPGs, in particular, became difficult to justify against all the other stuff you had to get done.
There's a reason so many of us started playing much more regularly in the past decade or so: that huge glut of teenagers from the 80s reached a point where devoting the time necessary to maintain a campaign became feasible again. Our kids got older, our job situation more predictable, our finances more secure, etc.
I think a lot of 5e's glut of players is hitting that same age, so that will lead to an inevitable contraction. The way to ameliorate it is to make the game less of a time and money sink, and I think WotC is trying to do this by making it much more digital. DnDBeyond certainly saves me hours each week. But I don't think this will soften the blow that much. People just age out of things.
Another reason players might leave is that they got burned out, like what you describe. Again, I think chasing those players is not a great strategy. Those players are looking for novelty, so in effect you are competing with other games that they could go buy. But if you change D&D so much that it feels as novel to them as Call of Cthulhu or something, you are likely to alienate a much bigger swathe of fans who were happy with the game as it is. That is actually what happened with 4e, which tried to change D&D into a World of Warcraft-style game. That is why WotC are going in exactly the opposite direction with OneD&D.
Another option is to create novel settings for the game. Maybe you can stop some folks from leaving for Call of Cthulhu by offering a Cthulhu-like setting for D&D! But this can be ultimately a trap, as TSR discovered, that leads to fragmenting and cannibalizing your own fanbase. So WotC know that their new settings have to remain close enough that you don't risk turning someone into, say, a Dark Suns player rather than a D&D player.
To be blunt, OP, players leaving because of burnout or for life reasons is inevitable, and WotC have indicated through OneD&D that they aren't really going to chase after those players too hard. They are trying to create a stable brand that can continually attract new, young players while remaining recognizable to those older players who want to return. In particular, chasing players like you who need novelty is a bad idea. They can't be as different as the many other options that are out there for you, nor should they try. There are a ton of great games - play them instead! And they intend to keep D&D waiting for if and when you want to come back.
TLDR: basically, WotC are turning D&D into McDonalds. They've got a formula that works (5e) and they are sticking with it. They will add novelty at the edges of the menu, but ultimately, this is the burger and fries of RPGs. And that means it's not going to work for everyone, because nothing works for everyone. But it works for a lot.
