A successful company needs to sell something scarce. Open source software is by definition not really a scarce good, so you need to find something adjacent to it that is, and that can be a lot trickier.
> relies on copyright and patent law to enforce a monopoly
Correct. As well as SaaS business models which make that even easier and less dependent on sometimes difficult to enforce rules to make the product scarce.
I genuinely don't understand what the point of bringing up copyright here is. Apart from a tiny handful of materials, even physical products rely on legal protections against counterfeits and knockoffs to be scarce. Why do we talk about software as if it's the first and only thing to be artificially scarce?
No it isn't scarce. There isn't a limited supply. There is no point at which the software company would say "sorry, we're out of stock". Unless maybe you are selling physical media with the software on it. With SaaS, possibly you are constrained by the capacity of your infrastructure, but that isn't usually a practical concern unless you have incredibly unexpected growth.
Well, for closed-source software there's a scarcity of suppliers, not supply.
The value is not in "a copy of windows" it's that all copies of windows come from one supplier.
Yes there can be competing products, that achieve the same goals, or there may be scarcity there too.
Of course, even when achieving the same goals, some products are more desirable than others. There's no scarcity of OS options, but some would seem to be more popular.
It has had artificial scarcity introduced to provide an incentive to create it. It's certainly an imperfect system in many ways, but it kinda sort does create scarcity that drives revenue which pays programmers to keep working on the software.