Although the return of buying currency is high, the risk and return coexist, so investors also need to bear the risk of the currency price falling. And mining money is drought and flood guarantee. As an investor, we should take a long-term view of mining machine production.
Well, at the end of the day, it all boils down to the personal preference of the investor.
Personally, I would prefer to purchase BTC compared to mining BTC. The problem with mining stems from its very nature that you have to purchase the suitable and right mining equipment. This entails that you have to allocate at least a significant amount of capital to start such business. In addition, you also must have a suitable location on where to place these mining rigs since it has to be placed in a cool location.
As someone who wants to avoid the hassle of maintaining such equipments and lacks the necessary knowledge of mining, the convenient way would be to purchase BTCs and leave them for long-term HODLing.