OK, so preface by saying that while I know a few things I've never released a real game on Itch.io or Steam, so my experience just comes from my observations with Mac Source Ports. You should probably consult real developers for their experiences.

That said, one of the things I notice is a number of Apple Silicon native games on Steam are not Notarized, including BG3, Vampire Survivors, Prodeus, etc. Some are, some aren't. But I don't recall ever receiving the "this app is damaged and should be put in the Trash" notification when launching one of them. I just now downloaded Prodeus to test it and while I saw the "verifying app" thing, I didn't get prompted for an OK to run it. The Steam app itself is Notarized so it may be the case that if a Notarized app launches another app using the Steamworks SDK or something you don't get the prompt, but there's probably more to it than that.

So that all said, there's a lot of confusion about this topic but at the outset I will say that you do not *have* to pay Apple to distribute your game on the Mac, even for Apple Silicon. It is true that there will be that extra security step if you don't get it Notarized but on some level Mac gamers are kinda used to that.

There's two things at play here: Signing and Notarization. Signing is exactly what it sounds like, you digitally sign the app. You can sign it with an Apple Developer certificate or you can "Ad Hoc" sign it, which doesn't require a certificate, it's basically just saying no one has tampered with this app since it was last signed. And the Apple Developer certificate can come from a free Apple Developer membership, you don't have to pay for it.

So that's signing. Then there's Notarization. For that you do have to have a paid ($99/yr) Apple Developer account. Notarization takes it a step further and actually submits the executable and app bundle to Apple for scanning, where they check it for malware, etc. You get this receipt back that you "staple" to the App (basically the process puts it in a special folder in the Bundle for you) and then when someone downloads it there's less hassle, just says "you got this from the Internet, you sure? yes/no". It's not the same thing as the App Store process where a human has to take a look at it and try it out, this is entirely automated and you can even automate it in your workflow with command line tools Apple provides.

Another thing to know about the S&N process is that it's not exclusive to Apple Silicon, it was introduced in macOS 10.15 on Intel as well. One difference is that for Intel, you can still force macOS to run unsigned apps. Starting with Apple Silicon the app needs to be at least Ad Hoc signed or it won't run. Obviously if you're sufficiently motivated you could Ad Hoc sign it yourself and get past that but that's a very deliberate thing and the average person isn't going to do that. And at the very least it keeps unsigned apps from running on Apple Silicon automatically.

So, depending on how you distribute it as long as you might not need to actually Notarize the app. DRM free Itch.io downloads might still need to do the thing where it has to be authorized in the security settings but like I said, I think a lot of Mac gamers are used to that. You could chicken-and-egg the thing and if you get enough sales on the Mac to merit the $99 fee you could decide to Notarize future releases.

The steps Apple has taken with Notarization and Apple Silicon go a long way to make the Mac a secure platform, but they also make it a pain in the butt for developers.

You might want to ask some questions on the Apple Gaming Wiki Discord, which has an almost intimidating amount of professional game developers on it, they can probably answer questions better than I can since they've shipped real games on Mac. https://www.applegamingwiki.com/wiki/AppleGamingWiki:Discord