Even Linux hasn't "won" in those areas. It has just replaced what we would call a common API layer or a communication standard. The virtualization products are still proprietary. Servers and their firmware are too. People needed a Unix-like OS that hasn't been riddled with patent issues and wasn't outrageously expensive. They needed it because they were also price-sensitive or outright cheap. They didn't want to change APIs or modularize their software. Linux was there. Startup culture happened which demanded cutting all the costs you can. Linux was free of charge. Linux wasn't the best OS for the job sometimes. But it was there and it was gratis. So it became the middleware for Unix-compatible software.

We have open standards and even open/free software for anything that companies aren't making money out of. FOSS by itself cannot make money. In places where software matters the most or, if the software hides the trade secrets the most or, if it is the main money maker, creating FOSS is economically infeasible.

For FOSS to win, we need to change the economic and legal system. Current capitalist system in many West-aligned countries is actively hostile against sharing in any kind, except the ones that profit the biggest players in their non-critical areas. In a market where the first one to market gets to buy all competitors, in a market the one that has the biggest secrecy wins and gets all the money from investors like Y-Combinator, there cannot be any truly FOSS software-only products. They need to do rug pulls to support the exponential growth. Startup culture is fundamentally anti-FOSS. It is pro-FOSS in only consuming. Even a startup releasing some middleware can be interpreted as mishandling investment.

We need to make sure our governments support FOSS infrastructure and FOSS user-facing software. They need to be equal employers and competitors to Big Tech or they need to directly support smaller competitors for decades. Otherwise, I am afraid, FOSS cannot win.

Corporations are not really a capitalist thing. They get misconstrued as one.