Even positive cash flow isn't a 100% Guarantee. Eventually technology companies will be impacted by the greater economy. Ad revenue and luxury purchases will be hit by a real down turn. How do you justify a 30x P/E ratio if your market segment is flat? Down quarters happen. Apple had massive upgrades this year but how long until the next major overhaul? And if your staring down massive food price inflation do you still go out and buy a new phone? some will but a lot won't. They're also running into supply constraints. How much more screen space can google take up with ads?
Possibly, hard to tell. Corporate profits are at record highs[0], so while it might be difficult to justify Tesla P/E ratio, you can't say no one cares about profits anymore. These companies are flush with cash and buying up anyone with a half-baked idea, but it's hard to blame them.
We also are not even close to the most profitable stretch in stock market history. We are likely due for a correction somewhere as corporate debt pushes higher and higher [1], but even long profitable periods of the markets can be marred by corrections (if the fed lets the corrections happen).
I don't know, these gloom and doom articles spread fud and I think that if anyone could pin down when and where and the size of the correction, they should make those investments and make bank. Otherwise, the fundamentals of investing should remain the same.
[0] https://www.bloomberg.com/news/articles/2021-12-06/stock-mar... https://tradingeconomics.com/united-states/corporate-profits
[1] https://www.wsj.com/articles/pandemic-supercharged-corporate...