If they can actually produce the product they claim, I don’t think failing to break in to the market will be much of a concern. They’d be in a league of their own. However, if the tech doesn’t actually work they way they claim, or if competing tech can do the job better, then they’ll go nowhere.
Realistically, if they deliver on the product they claim to have they’re not going to last long but not because the company fails. They’ll be swept up by a bigger player in the industry.
And of course these days with AWS, the other risk is Amazon going "yeah we're just going to literally steal your idea and make our own, and there's nothing you can do about it because no lawsuit you bring would fine us an amount we can't just write off as a business expense" if it'll save them enough money.