As a licensee, your royalty (and royalty-reporting) obligations are triggered when your game as earned royalty outside of the royalty-exclusions listed in the EULA. Therefore, if you game earns nothing (or less than $3,000) in a quarter, you have no obligation to Epic.
That said, you certainly have no obligation to keep your game on the market, and most distribution mechanisms don’t require you to keep selling your game.
One concern that I have is, “What happens 30, 40, 50+ years from now?”
Chances are, an indie title will not be earning $3,000 per quarter, or anywhere close to it, decades after release. Is there a way to stop reporting until you have quarters with actual revenue owed? Failing that, is there a way to declare your game as “off the market”, assuming your distribution channel (Steam, your website, etc.) allows you to pull your content?