I think there are a lot of proven systems, and they all work. Whether they are white hat or black hat techniques.

There is one main reason why people don't succeed.

They lack focus and are unsure which way to go with creating an income online.

There are so many ways from just acting as arbitrage where you pay for traffic straight to a cpa/affiliate offer, doing all the blogging, list building, YouTube videos, providing free content, creating courses, creating products, writing for kindle, creating software, Amazon fulfilment, eBay, Shopify, cryptocurrency, hedge betting, niche websites and many more.

So you need to choose one tactic that suits your strengths and abilities and stick with. Stick to a plan and checklist with that strategy. And like you said don't go after the shiny objects.

As for emails keep a few especially those that you opened, because they had a trigger in there that made you open them. You can see how other market to you. Is it full on or is it stories or do they sell more than one item in the emails. How may times do they send you, is it weekly, daily or more than once a day. Is it pure selling or content as well.

Once your first strategy is working, then you may want to move on, while you outsource the work of the other strategy.