Let me start with, crypto as an investment is stupid. But, it really is too bad if it fails. It would be nice to have a replacement for cash that has a similar anonymity to cash.
Look, I'm not looking to do anything illegal or illicit but the situation of today where Visa could conceivably sell my purchase history to Google who would then target advertising to me or be able to provide the number of Snickers bars I ate this past year to health care or insurance providers doesn't sit particularly well with me either. So being able to purchase some groceries, clothes, etc through electronic means but in an anonymous fashion has a certain draw for me.