If I give you a free beer, you have one beer. If I give you the recipe, you can make your own beer. You do have to make your own open source beer or you can hire someone to do it for you or perhaps take you through the steps a few times until you’ve got it. With luck there will be a community of open source beer brewers with whom you can interact and improve those recipes.
Free software is free until it isn’t! The illicit drugs industry works in a similar way (the first hit is for free).
Similar story here. Again, no way do these things get to the internet. I use Zoneminder. Reasonable price and a decent image - night and day. Rock solid stability - I’ve never rebooted one to solve an issue. Their up times match firmware updates.