Ads in desktop software are dead. Also, just think of the amount of serious, transient eyeball traffic you'd need which sounds like an unlikely demographic for a Mac app. Especially if you think these same people would be interested in your Patreon. You'd basically have to burn all goodwill to make a few pennies off them.

The only reason ads make a little money on mobile is because of the lack of adblocker penetration + low tech-savviness + compulsive mobile games. When was the last time you even used a desktop app with ads?

Donations aren't a source of income. Though I encourage you to try a tip jar like Patreon just to see how vanishingly impossible it is.

Sounds like you're still deciding if you even are trying to make money. But make no mistake: you won't luck into money by writing cool blog posts and building free features that people ask for.

Building a revenue channel into your application with IAP sounds like the only thing that has a shot and the only thing that might align with your goals.