I am not sure how others here will feel about this, but if you cannot take a business to $5000 per month in almost any market, then it might be more of a "you" problem (I don't have the right skills, I don't know how to sell, etc) than a "I chose the wrong business" problem...
Maybe the reason why business #5 or #6 is more successful is not that they changed businesses, but that they finally developed the skills necessary to make it work through their failures. If they went back to business #1, they could probably make it work this time.
Takeaway? Chose one thing and develop the skills (sales, etc) instead of jumping to the next thing.
If we are talking about $500K per month, then that is a different story...
I can handle the downvotes...