They could make it paid only today, and it’d be instantly profitable. Most free users would transition to a free alternative, but the corporate world would easily pay for use. So would some power users. But I’m sure they are making good money with all the API use anyways, the free access is a cheap way to get mass testing and training data.
I’d expect a “Ultra-tier” fast charging station to have internal batteries (or perhaps supercapacitors or something like that) which buffer up from the grid. Eg. when not in use and over-night. Probably won’t last much into a day even with that, but we may see smaller buildings connected to charging stations that hold internal batteries to deliver faster charging than the connected grid can deliver.
As long as there is demand and profit to be made, it could happen. The biggest cost is of course the batteries, but if solid-state batteries turn into reality I think things might be more cost effective. Especially since fixed position batteries aren’t subject to the same contraints as car batteries. Don’t need to handle vibration, weight is not a big problem. Key goals are lifetime value, energy density + and (dis)charging rates.
Cheaper electricity during night might not be a thing everywhere or in the future, but small savings by stocking up cheaper during nighttime, gives better margins.
I use sync, but I think they still should be FOSS, or at least open source. Just because when anything gets left behind or never fixed, you can take it and patch it up yourself. That includes clients too, lots of good clients that get left behind because Dev stopped and whatever they were interfacing with changed.