I share your worry about economic strife leading to fascism, but I am native German, so have a bit of a biased view there.
> I wonder how long it will be before various governments start stepping in and regulating them out of existence.
I expect "out of existence" won't happen, because there's too much money in it now by the banking sector. I expect there will be regulation. The bill that's being considered in the US looks like it might be enacted elsewhere in the Western world in a similar fashion: Crypto currencies that are decentralized are commodities (BTC, maybe ETH); cryptocurrencies that are under the control of a central entity are securities (most everything else). Since securities can only be bought/sold with registration (in the US, SEC; elsewhere, its equivalent), this would likely wipe out 98% of the crypto market, but by coins, not by volume. By volume, the market is dominated by a few large coins, and they'll likely be fine.