I understand re TFF. I walked away in 2013. I only recently started posting again. So far it has not been bad, but there is more incorrect info there than here.
Everything we do in this hobby is based on science. Water chemistry can drive you nuts if you do not understand what underlies it. Moving water is physics, selecting fish involves knowledge about how fish socialize, how they reproduce, what sort of diet they need etc. All of this has been studied and researched over the decades. Even the habitat needs of the fish are relevant to setting up a successful tank.
How many fish keepers know the name of any of the nitrifying bacteria that are in their tank? This involves microbiology.
It is possible to blunder through all of this and manage to have a decent tank, but it is a lot easier the more one knows.
And it all comes full circle- "You can lead a fish keeper to water, but you can't make them think."