startups, while they can have funding, do not have near unlimited piles of cash allowing them to keep building something no one wants. At some point, they have

startups, while they can have funding, do not have near unlimited piles of cash allowing them to keep building something no one wants. At some point, they have to start being profitable, and this constraint is what forces them to be adaptable and listen to users. Billionaire pet projects do not have this constraint, and as such can become endless money sinks.