Are all these Youtube Drop-Ship Gurus Scammers?

I don't know what and who to believe anymore.

They all do the same things:

-Post Youtube videos with tips for a few months;

-Post Shopify screenshots (easy to modify, even with coding, Photoshop or mass self-orders on your store);

-Sell their courses.

Some seem legit, others don't.

They could make money with their courses but how many people are willing to buy from them?

What are some NO BS courses and videos I should watch/buy ?