To make money people say you should solve a problem. How much you make is then just dependent on the value people give to the problem.
It is the same how someone may earn less, because their perceived value is less. The perceived value of top sportsman is a whole lot more, and that is the world we live in.
So back to the main theory, solve a problem that has value and you will make money from that.
Some problems though may seem like they require a solution but they can only be achieved in a set time. Such as doing a repair for someone, you can realistically only do so many repairs, and to do more might require more labour which makes scaling difficult.
If you can however do something once and present it as a solution indefinitely then you have no scaling issues. This would be similar to yoga classes, or any type of class really.
This is where I start finding an issue with the whole idea, and likely it is just because I am a very pessimistic person. But I don't have any problems aside from being poor that I need a solution for.
I also tend to not see problems others supposedly face as worth much purely because most people are a little bit "whiney" as it is.
In a world where everything is an issue I dare say nothing is an issue.
Yet, people are making bank, supposedly, I think the ones we are bombarded with as making bank obviously are not doing so through the actual channels they say.
They are misdirecting your attention, not to say it is not a viable option.
Surely it must be a viable option to accumulate "followers" and give them busy work to distract from the actual value they provide.
Which is their attention.
So I find it very hard to think of problems that are worth solving when all roads lead to harnessing others attention. Sure you will probably sell one or two courses to the absolute most naive and that gives some legitimacy to the fact that you teaching about how to sell a course that is about selling a course, is a problem worth solving.
Maybe the simplest thing is just to ask:
How can I help you today?