Why do a lot of governments tax Cryptocurrencies in the same way as Shares?

I'm not sure if this has been asked before. Cryptocurrencies are generally unregulated and have a lack of regulatory protections; they are generally considered a very risky asset class. For example, there is no legal protection for losses of funds from cryptocurrency exchanges if they get hacked or go out of business. So why do a lot of governments tax them in the same way as shares for example, which are much more heavily protected and generally lower risk?

It just seems a bit unfair.

(I'm from the UK)