Ah, OK, so I think your point is more along the lines of “it’s relatively irrelevant” which I really didn’t even take into consideration given the already significant effects of crypto (for example in terms of CO2 emissions which are already about 0.1% of total emissions) and the extreme growth the market has seen and is seeing.
I would say the percentage of transactions is not really the main factor here, more the wealth held in it, and crypto already is well on it’s way of holding 1% of the world’s wealth.
Maybe you don’t believe it solves any genuine problem for you in particular or for society as whole, but creating money out of nothing clearly is a very powerful tool if you happen to wield it, so I don’t see it going anywhere.
Even if it does end up just being used in the black market economy, that is estimated to be >10% of global GDP.
Here is documentary that might give you an impression how creating new local currencies can successfully solve real-world problems, blockchain technology fits very well into that because of it’s decentralized and digital nature, making it a lot easier to create, distribute and convert currencies (although the documentary doesn’t focus on that aspect, but is explained more in depth on the website).
And here some research:
https://www.grassrootseconomics.org/research