>There is zero profit to be made at the end of the chain.

Think of all the "sales" that comprise such things as space missions (ones without immediate real-world use) or large hadron collider. Or any other large, expensive, long scientific project. If you measure the outcome purely in money within decades, these things can be said to be zero or negative profit.

How much profit was at the end of the chain of the current Artemis lunar mission? Well, zero or negative, but lots of companies and people up the chain made meaningful progress and made a living. Quantum computing is just like that in my opinion.

The biggest problem in my eyes is the "game" of commercialization. This technology is in early research phase, but it's so expensive and not immediately game-changing that the public funding was never enough. So, companies started to play the "we sell products" and "we do IPO" games, which IMO doesn't make sense.