I could see timed exclusives, e.g. a digital pre-release of a new book ahead of the physical copy. Alternatively, I could see individual releases online, with physical book compilations coming later. This has the potential to be great, because they can get very targeted feedback on how something actually plays in a way they couldn't in a pre-release state, and apply errata to it, before it gets enshrined in immutable physical copy; almost like everything getting a second UA with a much broader audience. (Many tables, including all AL ones, don't allow UA at all for instance.)
Corollary to this - physical releases/products are heavily dependent on traditional supply chains, which have proven to be highly unstable in this industry. WotC are not as exposed to that as the likes of, say, Games Workshop, but they're still susceptible.
Some people just want a rudimentary experience - testing builds, demoing combat encounters before game day, "how should I change this fight if Jim can't show up" etc. An AI DM would be able to run such things in an interesting way.
Most such uproars are 👍
First, I don't think it's about "proving you wrong." Everyone has their own things they value, especially monetarily, and different financial situations to boot; yours and mine not being in alignment does not make either of us wrong.
But to answer your question: $30/mo is as others have said a hefty price tag, moreso even than MMOs which are playable purely solo, or GamePass which has literally hundreds of unique experiences built in. So I don't know that they could offer anything that's worth that much specifically - unless maybe it meant not having to buy any future book releases either, which I think would be a loss for them.
But reframing your question more broadly into something like "what would make it worth your while to pay more than the $6 /mo you currently pay?" I've listed a number of these features already, but to reiterate: The 3D VTT, AI DMing, early access to new releases, some form of homebrew curation, free giveaways like they've been doing, priority queue for new feature suggestions - things like that would definitely get me to spend more recurrently than I do today.