I don't get the part about Homebrew. If you're using Homebrew, it doesn't make a ton of sense to use Itch.io. Just use Homebrew. Seems like a more appropriate place to distribute a dev tool anyway. You could set up a patreon and print a link to it when appropriate. That's basically what Vim does.
I agree that Apple is dumb of course.
homebrew voluntarily applies the quarantine flag on casks (ex: apps) so you still need to pay the apple dev tax to distribute your mini app that way, itch.io does not so you don't get the lying scarewall
They want to have a way for users to pay them. Itch.io has that, homebrew doesn't.