I wouldn't call what you stated here as advice given because every one of us that is doing something differently, doesn't mean such things are been fruitful to us. There are things one could engage in and it won't be that fruitful to them no matter how long they try. You don't advise such a person to stick with that for long without having some other things they can highly think of to do. Remember, in today's economy, having a single source of income is not advice. Having a diverse side hustle is encouraged. The advice should be to try hard to be consistent in them all because you don't know the exact one that will later pay off in the future
Same goes for doing a common thing. Sometimes it is actually better to do things that are out of the norm. There are just down times in life and then not all that we start to venture will get us the result that we want. It can also give us some test first before we achieve the success, so we just keep on moving. If one doesn't work, then try again on the other, though I think there might be some who are destined to be doomed and fail forever but at least they are still alive and maybe they can still find happiness on other simple things instead. We can seek advice but we can also experiment and add more to it, especially if it doesn't work well.