Okk I get it but a lot of other apps do the same… consider that from our perspective the alternative would be to run a standard subscription. Is that preferable? Personally I would say no, but maybe it’s just me.
honestly the main issue is just that the value provided by a gui for a package manager i can already make use of isn't worth $49 to me (and many others i'd wager), and it certainly isn't worth paying multiple times for. i'm sure the features you have planned are cool but it's still just a front end for homebrew whichever way you look at it.
i don't mean to diminish your work at all - it really does look great and i mean that, and hopefully you'll prove me wrong, but i don't think you've properly considered what value this actually provides to the people you want to buy it.
you might say that $49 + an annual subscription (and it is a subscription by the way, you can call it what you like but that's objectively what it is) is what you need to charge in order to make the time/effort you spent on development worth it for you, which is fair, but consider it from the POV of a potential customer: it's $49 + an annual subscription for a prettier way to achieve something that they probably use quite rarely, something they can already do, and something which there are already free alternatives to.
consider something like bettermouse (https://better-mouse.com). macOS is borderline unusable without it, i'd sell my computer and switch to linux that same week if bettermouse disappeared. i make use of it for 100% of the time i use my computer, and it costs $7.99 one time, forever. the developer could double or even triple the price, and it still wouldn't even be half of what you're asking for.