Interesting and possibly exceptional counter example here.

I worked for a product company and I was supposed to add a set of new features to the product.

The way the company was setup, we were able to setup demos/calls with existing customers quite quickly.

Two of the existing customers are industry giants and as I walked them through the demo, they were able to actually name the exact API calls I would have been using for the demo. And then one of them actually effectively said "take my money already and ship it"

I quite lieterally asked them if they had such fine grained information on what we were going to sell them, then why are they even bothering to buy from us ?

The answer was, getting a well packaged solution as a feature set in a product they are already using is far more useful for them than to have to spend time themselves writing ad-hoc/free-standing programs which do the same things even if they have the resources to do it themselves.

It's more than that too. Sometimes the companies have the knowledge and skill, they just don't have the time. Their engineer might have a list of 15 things to do, and if there's a tool that accomplishes #15, just pay for it and take it off their list.

If you can solve a very specific issue for any enterprise, there is usually money to be made. Enterprises have very specific problems, often problems that only exist in that that enterprise, and they have huge amounts of cash to throw at solutions.