Contrary to popular understanding, almost every major bubble has been reported as such before the fact. When Bitcoin was running up, everyone said it was a bubble. Read issues of the Economist from 04/05, they even had a cover story on the housing bubble. Before 2001, we had "irrational exuberance" (and the Fed choosing to cut rates into a boom). Before inflation in the 1970s, read minutes from the Fed...literally three or four years before multiple board members said: "There is going to be significant inflation". Before multiple currency crises in Britain through the 1960/70s, again BoE was telling govt: "If you continue you will cause inflation and devalue" (amazingly, one prime minister was actually responsible for both devaluations in this period). Go back even further, I read a paper about the Bicycle Bubble in Britain in the 1870s...again, lots of press about how it was a bubble.
It isn't hard. These aren't "black swans". This is human nature, it never changes. Because something is not happening now, does not mean it can never happened (incidentally, when these things do pop...you usually have a year plus to get out...humans are slow).
The amount of self-important puffery going on in tech is somewhat unique (the people involved are unusually insufferable) but it will burst. No path to profitability for most tech companies, most will go to zero. This has happened with every innovation, every capital cycle since the early 19th century. Again: not hard.
Also: it isn't just tech. It is technology innovation plus the most short-sighted practice of monetary policy in history. What is happening in Europe and Japan is staggeringly dumb (I am glad I will live to see the fallout from this group of self-appointed "experts" using all this massive intellect to drive the economy off a cliff).