>> both will struggle hard to actually turn a profit some day, let alone make back the massive investments they've received.

I'd agree with you, except I've heard this argument before. Amazon, Google, Facebook all burned lots of cash, and folks were convinced they would fail.

On the other hand plenty burned cash and did fail. So could go either way.

I expect, once the market consolidates to 2 big engines, they'll make bonkers money. There will be winners and losers. But I can't tell you which is which yet.