Those simple strategies you undermine are enough for you if you work on yourself. I was shocked when I realised someone bought a trading strategy for $3,700...oh my God!

And guess what, it failed him, what a waste!
A good trading strategy is important, but what traders need to succeed is not an absolute strategy that gives 100% winning. A 60% winning strategy is okay if you can work on your
trading psychology and
money/risk management. As simple as the two are, they've reshaped my trading results for good.
Reshuffle that mindset and see the result in months.
I can promise you that not everyone has a good strategy.
That could be argued though. Let's start by you giving me an example of a bad trading strategy that people use. Don't forget, we need to establish the difference between having a bad strategy and using the strategy badly. For me, I've not seen a bad trading strategy, but I've seen countless traders using their strategies wrongly.
Those who opt to pay someone for that strategy are those who want to earn profits fast. Because they thought, the strategy will also work on their end.
You are right! Additionally, they buy it possibly because they do not have the time to go through the proper channel of gaining more experience to build their strategy. Many also do not have that creativity, and they never believed in themselves.