If (when) new people stop buying into a pyramid scheme, all they have are worthless tokens nobody else wants.
If new people stop buying into AAPL or GOOG, all shareholders have is a share of a massive pile of cash and a business which generates billions in profit every quarter. For related reasons, people are likely to continue buying into AAPL or GOOG, AAPL and GOOG can buy back their own shares or find other investors easily if a major investor wants out, and even if for some strange reason nobody at all wants AAPL or GOOGL, shareholders would still expect to get back what they paid in dividends in the long run by holding.
Of course, the businesses can still underperform expectations or fail, but there's a difference between an investment that underperforms because the company isn't good enough at making money and an "investment" that will eventually fail because there isn't actually anyone making money out of anyone other than "investors"
If new people stop buying into AAPL or GOOG, all shareholders have is a share of a massive pile of cash and a business which generates billions in profit every quarter. For related reasons, people are likely to continue buying into AAPL or GOOG, AAPL and GOOG can buy back their own shares or find other investors easily if a major investor wants out, and even if for some strange reason nobody at all wants AAPL or GOOGL, shareholders would still expect to get back what they paid in dividends in the long run by holding.
Of course, the businesses can still underperform expectations or fail, but there's a difference between an investment that underperforms because the company isn't good enough at making money and an "investment" that will eventually fail because there isn't actually anyone making money out of anyone other than "investors"