we should be careful about trusting individual self-proclaimed Marxists

I agree with this, which is why I don’t read or quote from them, but their work might be relevant to others which is why they seem popular.

and instead should work more to propagate and organise the material that already exists

marxists.org is a great resource but doesn’t actually have Xi Jinping’s work on it, or any of the past 3 Chinese leaders for that matter, even though they are available in Chinese and English from official sources. ProleWiki is what this site promotes, though more work is definitely needed.