In 40 years, the Nasdaq 100 has risen for 33 years and fallen for only 7 years, with a probability of increase as high as 75%.

During every major crisis, the Nasdaq experiences a sharp decline. But each time, it manages to bounce back, often rising even more sharply afterward.
The long-term annualized return is about 10.6%. Many people might think, "Only 10%," but that's 10.6% compounded.
Suppose you invested $100k in 1986; by now, it would be worth $5.62 million.
For ordinary people, that's basically enough.