Interestingly / Ironically / Whateverally, it doesn't cover a ton of other, non-iOS users. This may be a push to Desktop Safari usage, but I am really uninterested in supporting proprietary browser tech, especially when there are competing open standards, doubly-especially when (as the OP mentioned) Safari in particular doesn't seem interested in supporting other open, interesting APIs.
Service Workers from what I've seen would consume quite a significant amount of battery life and prevent Safari from sleeping under most conditions.
If you are selling physical goods then you can use apple pay. If you were already in the app store, you would have already been using credit cards (and probably apple pay) to process payments instead of in-app purchases.
If your hybrid app is currently using in-app purchases, then you should still be using in-app purchases.
