Ah, the internet, where anybody can pretend to know anything, and as long as they stay close enough to plausibility, it's unlikely they'll get called on their crap - and if they do, they can hide or obfuscate or deny or point to nebulous 'facts' to prove their case. We all get this by now, right?
We're fools if we don't. But in a community of enthusiasts, it's also reasonable to expect that there will be a bunch of people who know a LOT about what they're talking about. Most of us will find those folks and listen to them, rather than others who show up and can't substantiate anything. That's not to say these others are bad people. They may simply be uninformed. The problem comes when they double down and won't admit they got this on wrong.
(If you ever see me purporting to know anything on the DB side of this forum, assume I'm delusional, or that my account's been hacked.)
But think what 'advice on the internet' means for good. I can get answers in minutes (which I then filter based on a number of factors) that might have taken me days to find elsewhere. Anybody remember those weird phone books at the public library? Or digging through microfiche looking to find the right article in a scholarly journal? Because of this forum, I can ask questions and maybe I'll get answers from people like me, who have an opinion or some real-world experience, and maybe I'll get the guy or gal who invented the darn thing. That's cool - and both are valuable in their own way.