I agree that they need to be open source. But that makes it really hard to make a successful business. Sure, there are examples of success, but also many examples of successful open source tools never becoming successful companies.
The most famous example is Sendmail (where I worked way back in the day). They took millions in funding and ultimately sold to an infra company, returning pennies on the dollar to their investors.
The difficulty stems from the fact that your customers are developers and operators, and they all think that they don't need you because they are perfectly capable of running the software themselves and adding whatever they need to it. In a lot of cases they are right.
And now, with AI coders, it gets 10 times worse, because they can take your open source and then vibe code a "good enough" version of your commercial product.
I don't know how to square this circle. There are a lot of great dev tools made by people for free for the love of the game. But even those people need to eat.
Some tools have started making licenses that are free for individuals and startups but cost money for profitable companies. That's an interesting strategy but I know some companies won't allow those tools precisely because of their license.