The filter is voluntary for ISPs to join, and the Department of Internal Affairs (which runs it) doesn't have the power to make it mandatory.
Also the Office of Film and Literature Classification lets you look at the classifications for everything online (including stuff that is banned), IIRC with a reason as to why it was classified the way it was.
These days Mojang provides obfuscation maps, so you can work with proper class and method names (though no parameter or local variable names). There's also been a lot of effort been put into the tooling. Nowadays there exists Gradle plugins that will download the game jar, decompile it and deobfuscate it using the official mappings. You develop against the deobfuscated code, then the plugin will turn the unobfuscated names back into their obfuscated versions when you compile.
There's also been technology developed that lets you easily modify specific parts of a method in the game, so you can e.g. insert calls to your own functions at runtime.[1] This saves from you having to modify the game jar itself.
I experienced exactly the same. I suspect that since they're optimising for engagement, already having watched a video is some indication that you'll engage with it again.
Bedrock Edition is primarily targetted at the consoles (where running the Java-based Java Edition was difficult). Java Edition is still worked on (and runs on Linux) and they are trying to achieve parity between the two versions.
Also the Office of Film and Literature Classification lets you look at the classifications for everything online (including stuff that is banned), IIRC with a reason as to why it was classified the way it was.