Sad, yes, but that's the world we live in. There's really no such thing as a "safe, modest bet" - that lifestyle business that provides you a good living now will cease to provide you a good living soon after a big competitor decides to move into your space. Similarly, even working for the big competitor isn't all that safe: you could be laid off because your manager doesn't like you, or because your manager's manager doesn't like your manager, or because product priorities shifted around, or because you're suddenly the scapegoat for your company's sexual harassment culture, or because your company hit a revenue speedbump, or simply because shareholders & upper management get greedy.

Binary success ultimately comes from the customer: from their perspective, either the product satisfies their need or it doesn't. As soon as some other product satisfies their need better, they'll switch. And since customers talk to one another and largely like the same things, they tend to do so en-masse, and even $multi-billion giants can find their market evaporates in the span of a couple years.