In the last 30 years, we’ve had multiple bubbles in the tech industry. Every one of them was backed by real stuff that we still use today. They were still bubbles and a ton of people were hurt when they popped.
Specific things may be overvalued. I suspect data center real estate is a bubble, for instance.
The cryptocurrency bubble, however, didn't. Not really. At best you can use it to buy drugs. Some of the GPUs may have been repurposed for AI, but not enough to make a dent in AI, and the AI reesarchers who kicked off the AI bubble were having to buy their GPUs for high prices to compete with the miners, not low prices after they went bust, so we can't even say miners helped kick it off.
And many innocent people ended up being hurt in the process.
Bubbles are not good. They are harmful. The ability yo recoup some of the losses in the span of next 15 years does not make the bubbles something positive.
For example the Berlin Ringbahn was once some billionaire's toy but now it serves very useful traffic, as Berlin grew outwards to where the Ringbahn is.
> Bubbles are not good. They are harmful.