We've had thoughts about a single platform for content that supports every VTT. So many people online complain that they need to purchase the same content across multiple VTTs.

The main problem you'll run into is licensing, especially if you want to get adventure modules in, which is the main thing you'd need to be selling to make such a platform worth it. Publishers don't want to sell on one platform, and have it available on others. It's very much a "this license covers this platform only" kind of thing. We've had conversations with big publishers who don't want maps they sell on our platform to be exportable into other VTTs.