Apologies if this isn't the right subreddit, or if this has already been asked before. But here goes.

So I've read a lot of debate on both sides about the licenses that one should use for FOSS/OSS. There debates and discussions like this one which decry any FOSS license that isn't similar to the AGPL/GPL, and then there are posts like this one which say to avoid licenses like the GPL/AGPL because they're bad for business. From the HN discussion I linked to above, this post in that thread resonated with me but raised some vital questions:

The "infection" is the feature that makes GPL and AGPL useful. The basic idea is that if you are interfacing with the (A)GPL licensed software you are extending it's functionality and must comply with the license. The difference is that the interfacing with GPL is statically linking against the project. With AGPL the interfacing is also interfacing over the network. What this means is that software that clients or peers interacting with the software need to be available to the user. An additional stipulation for AGPL is that all necessary infrastructure to host the service be open sourced as well.

The reason for this is to prevent people from creating wrappers that allow them to profit off the licensed software without contributing back or open sourcing. The key thing to note is that you don't have to upstream changes. You only have to provide the source to users (and the license protections extend to them). This means you can still sell GPL and AGPL software but you do have to provide full usage permissions to the user once they've bought the product.

A vital question is about selling OSS. Say that I'm writing an awesome online game that I choose to license under the AGPL, but I'd like to sell it on Steam or itch.io. With each purchase, users get the source code as well as the compiled binary. However, a few months after the games release, someone posts the code on GitHub and causes me to lose a bunch of income because now everyone can just go over there and get the game for free. (This isn't just a hypothetical scenario, either -- I've seen people do this to other indie developers before.) According to the AGPL/GPL, or at least my understanding of it, I have absolutely zero legal defense or protection against this. There seems to be this "good faith" implication in these supposedly good OSS licenses, where your allowed to sell your software and there's this faith that's put into its users that they won't screw you over. Obviously, this is pretty much a utopian ideology, since we all know that the world is a far harsher place than this and people will screw you over if given the opportunity. But perhaps I'm misinterpreting the AGPL/GPL, and perhaps I'm wrong. So, I'm wondering... What is stopping anyone from screwing me over and potentially financially ruining me because I gave them access to the source code and they decided to go post it on GitHub/GitLab/etc?