There are 'DD' authors that manage to produce good insight and get 5-6 good predictions in a row but they are quite drown in other poor DD. See the ticker GME, someone with a pristine record predicted a GME pop following a console deal before the second COVID wave. Somehow he timed it perfectly (GME / Microsoft partnership annouced less than an hour after that post). That was a good DD and people apparantly made good money. Then it was followed by a tremendous amount of other poor posts (yolos, shitpost and 'gut feeling' DD) AFTER the surge. Without any information it is rather difficult to distinguish between the 'good' and 'bad' ones. There are some people tracking performances of different authors but I did not get to see an exhaustive study that would conclude one way or another.
Edit: ok nevermind the GME DD exemple. I tried to find it to link it here, but it is now deleted. People are claiming the author was a Microsoft Insider. Disclosing that info was highly illegal. I don't know what would be the legal ramifications of trading on illegal info when you don't know that said info is illegal. But I knwo that being investigated by a 3 letters agency is something you want to avoid.
Edit: ok nevermind the GME DD exemple. I tried to find it to link it here, but it is now deleted. People are claiming the author was a Microsoft Insider. Disclosing that info was highly illegal. I don't know what would be the legal ramifications of trading on illegal info when you don't know that said info is illegal. But I knwo that being investigated by a 3 letters agency is something you want to avoid.