The remaining quirks all feel related to Bluetooth tech and, specifically, the low-power available to AirPods (compared to, say, my giant Bose headphones).
I can only speculate but I think AirPods are currently limited by the bluetooth tech itself. What I expect we'll see is apple will ship a version with a proprietary radio system. They probably won't be compatible with non-Apple devices but they'll be 10x better than today's AirPods (more reliable, simultaneous audio from multiple devices, even better battery life, etc.).
There's no guarantee Apple will pull this off. But I'd bet it's far more likely there's a team of engineers dedicated to this strategy as we speak than that Apple just "gave up" on one of their best-selling product lines as soon as the MVP proved there was a huge market.