For every stock that took off, there are ten with which you would've lost your money.

That's bullshit, which shows you know nothing about investing.

It's unlikely that you would've actually held onto your investment. Looking back and thinking "I should've..." is the easiest way to make yourself feel miserable.

That's why funds exist that you can dump money into for x years.

Here in Germany a lot of people invested in the "amazing fintech company" Wirecard, because it was apparently bound to grow indefinitely.

Completely different than what you're talking about. Investing or spending money on something that is in alpha/beta is always a gamble, even outside of investments.