The thing I find the strangest is the fact that people don't want to be in control of their own wealth. It's so strange to think that you'd trust someone else with all of your money and not yourself. How stupid of a society do we have to be to keep the majority of our possessions in a bank?! Oh they have insurance, great. SO if they go bankrupt you get up to 100,000 back. Ok but anyone with 100,000 should just have their own money safely in their own arms. Having to rely on some company is completely ridiculous.
One word: "Sheeple"
The government has an insurance of 100k$/ per person (per bank in some countries) but they won't pay you interest rates for your lost time. Your 100k may lose its buying power completely during that time.
Unless you don't have anywhere to hide your money safely, depositing in a bank makes absolutely no sense.
That's why they are giving negative (or zero) interest rates. They want you to spend your money, they don't want you to save them. They are ripping us off.
When you have no cash (or some other asset as liquid as cash-might be gold or bitcoin), you will stay vulnerable to a financial crisis. They don't want you to stay liquid. They want to bury you down with Real Estate investments, Iphones, Car loans... When the shit hits the fan, you won't be able to lift a finger and banks will you rip you off one more time.
But in my opinion it is investment in real estate is a very good source of income. It does not matter what kind of property is residential or commercial.