I don't pretend to have the answers, and I strongly suspect cycles will still happen, for one reason or another. The timing and magnitude may be different.

The last tech bubble was based on speculation... folks were dumping a lot of money into a lot of ideas which never made a dime. Eventually folks wised up.

The next tech bubble may be coming, but it will be different. This time there are companies making billions, but for the most part what they are selling is discretionary, and even frivolous. If the consumers ever wise up (or get bored with it, or move on to some other fad), there could be a big letdown.

Also there's the problem of sustained revenue. Most of them can't charge a subscription. Traditional advertising has been a weak revenue source in tech, the big bucks is of course big data... and folks might eventually get tired of that too.

It's telling that big tech puts on a very progressive face here at home, but is bending over backwards to accommodate the government of China in their desire for limitations on access, search, etc. They are scared to not have access to that huge market, and any silly progressive ideas, such as human rights, are secondary to that access.