Top Grossing seems to me to be about 50/50 casual / core games.
The medium is more approachable, therefore attracts more casual gamers and many of these casual games have stunning graphics, physics and gameplay.
There are also games that require more serious skills, games like Pubg Mobile and to be honest, I like the mobile version more than the desktop version.
Mobile gaming is gaming now, if you count where gamers spend their money. Apple sell the easiest, most powerful mobile platforms for developers, and theres are loads of iOS exclusives as a result.
Big budget, cutting edge graphics, fiddly controls, single player big screen adventures... Those games are a shrinking niche for developers. And in that niche, MacOS can only be a 3rd place behind consoles and PCs.