Two valuable things are spending money on time because time produces money and when a person has only one source of income, he will be more worried about his future and more interested in saving. But my point is that saving money for investment becomes essential for people from middle-class households. So they leave the small interests for the big interests. So their investment is initially a waste of time.
TBH, I don't really get your point. The post that you commented, it explained that we don't only focus on saving but we also must have investment. Saving doesn't multiply our money along with time, meanwhile investment is raising the value of the money along with time. That's why investment is also important for our future because we may need more money in the future for various reasons.
There is no harm when people invest their money on trusted things. People can add the number of their investment gradually, even a low and middle class people can have good amount of investment if they do it continuously. For example when you invest in Bitcoin, by using DCA you can grow your investment for the long term holding effectively. Even you only have small or limited funds, it can be good amount of funds if we are disciplined to do DCA. Finally, someday we may have good investment, it is about how we can do it persistent and disciplined! It is untrue if it only wastes time, it deserves to do because it surely results in good profits if we understand how to invest in the right way.