In my opinion, it would be great to invest all the money. Because then our money will increase little by little, but if you save money we will decrease little by bit as well ...
Not good at all, you cannot put all your money because it means you are putting it on risk, matured investors will always think of the risk and will only put what he can afford to lose, never do that, it might make you bankrupt, be aware and let us not be too greedy for the money.
There are some instances where putting a substantial portion of your wealth into a single investment is worth mentioning, but for a lot of people they don't seek to exploit those investments and they go to other ones that they believe are better.
Either way, though, it is always better for people to only put in what they can afford to lose, regardless of what it may be. Same goes for gambling or literally anything else.