I think OP means that the community feeds a database using a platform they have no real control over, as the source code of the website/WebApp is not public.
However it is good to remind people that ProtonDB database is published under the Open Database License ODbL at this GitHub repo. To me having the db under an open license is more important than a WebApp (especially now that anyone can build such a website in a probably insecure way, using a 20$ monthly LLM subscription).
I haven’t digged into the db myself, maybe it does not come with the comments and so and only the borked, silver, gold, platinum labels.
So yes the website doesn’t seems to be open source but the database is. So anyone could rebuild an alternative from its database (which is probably the most precious part of ProtonDB). If nobody already did it yet, it’s probably because no one felt the need for, as ProtonDB already offer a valid, great and free user experience with currently no reasons to distrust the project.
Just have fun with your machine, learning is better when you are not forced to read the fucking manual. Of course you might need to do it but do it when you have the time on something you need to.
Of course distro-related forums are a great place to start, the legendary Arch Linux Wiki is a great place (even for other distros) and I know this might be contreversial but LLMs nowadays can be useful at explaining these kind of stuff to you, especially if you feed them the adequat ressources.
Often there is multiple best ways to achieve stuff and people are not agreeing on how. Of course there is often consensus on how NOT to do but doing and learning is better in my opinion than not doing because you’re scared it’s not the best way. Just do it!