This isn't an "Idler" in the sense that progression requires your constant participation and attention. The only things that happen "while you're not looking" are the ever-increasingly ridiculous timers associated with higher level item crafts, missions, upgrades, and so forth.
The game starts out with a wonderful pace and is quite engaging and charming. But that slowly starts to evaporate as you progress, everything takes longer, and there just isn't anything meaningful to "do" in the game unlike how it felt to first start playing it. The pacing curve drops fast, and it really doesn't bottom out.
Free to play games have to earn money somehow, I get it. But a one-time "make the pacing playable forever" is way more appealing than the idea of, "the pacing will always be terrible unless you're CONSTANTLY paying more money". I don't want to engage with a free to play game that will ultimately cost more than a World of Warcraft subscription to play through until it's "completion". This game is fun and charming, but it simply doesn't offer enough for what it ultimately will end up costing you to enjoy.
And while the monetization opportunities don't feel super invasion early in the game (they mention a deal to you once then stay quiet about it thereafter), sunk-cost-fallacy will absolutely crush people because of the pacing curve drop about a third of the way through the game.
If you play this, you'll naturally want to stop after just a couple of hours. Otherwise, feel free to enjoy what you're willing to tolerate. But there are better ways to spend your "not idling, actively playing" attention gaming time.
