Out of curiosity: what's your day job?
Are you getting royalties out of it?
Business software related, nothing to be proud of, no royalties, of course (and I expect none).
Well, then why expect others, who are doing practically the same as you, to receive royalties for their work? Just because you consider their work "an art"?
At the end of the day, the creative employees (programmers, graphics artists, musicians, etc.)
of a gaming software company are no different from the assembly line workers in a GM plant.
Both groups get monthly (or weekly)
paid a fixed salary, to get the work done for which they got hired.
Their head of department tells them: "Lucy, I need that and that kind of graphics, Billy, you create me that sort of music, and you, Josh, make sure it all runs together smoothly!".
There are no royalties involved on that work level.
On that level work heelers, that put their creativity -at a fixed price- at the disposal of the company they work for.
If these emplyees are lucky, they may get offered bonus payments - if
certain milestones are met at a pre-determined date.
And maybe (and that's a big maybe)
even a bonus payment after their work is done, if
certain sales expectations are met within a certain period of time.
But that's all. And they're well adviced to not count on it.
It would be something else, if we talk about big names in the industry, like Sid Meier, Hideo Kojima, John Romero, etc.
In these cases, we may assume that these guys could demand(!) a clause to be put in their contracts, that grant them royalties.
But even for those people, such clauses are not automated, and they usually come with a price/risk attached (as eric5h5 has already mentioned above)
: lesser or none pay during the development process, with both: the chance(!) of making more money in case of massive success, and the risk of making less than a fixed payment would have made them, in case of a financial failure.