The game Mindustry is one example.
Yes. And as you can see it has 14k reviews on steam while factorio has 141k reviews.
It’s also a game, so there is no productivity gain or loss associated with it. There is no on call IT support, but you also don’t need any and if something breaks, you lose nothing except the ability to play THIS game for a short while. It’s not a… webserver you run your online shop through where every hour of downtime costs you X hundreds of euros or dollars.
The game was also made by what looks like one guy. It’s not, you know libre office. With hundreds and thousands of contributors and a huge problem of how to distribute the money.
Of course you’re allowed to distribute it. And of course you’re allowed to charge for it. But realistically, nearly nobody would use it.
https://www.youtube.com/watch?v=8CfLt2jwZZs