There's a few reasons it doesn't have a cap, it's not meant to artificially create scarcity and to reward players and investors over many years to come in different ways. We also have plans to use the token, both as players and as the project, so it'll be more a balance between how much is being created compared to demand and how much is being burned. While it doesn't have a cap it doesn't mean we'll just wildly keep printing millions.
Hive works similarly in a way, once the inflation drops down to 0.5% yearly it'll go back to being inflationary as far as I understand.