Because fuck you, that's why.

Mostly it's because we buy them at those prices. 🤷

Capitalism and greed.

Well technically inflation does that for you, taking $ here, but $10 was worth more than 10 years ago than now. I understand where you are coming from and it makes sense, so also I might be wrong but hopefully there aren't too many games increasing their price as time goes on to account for inflation.

So the sales look better and the subscription services seem better value.

Do you have an example of such a game? No reduction after 10 years sounds really weird.