If anything, at this point (especially with more and more new coins adopting PoS rather than PoW) I'd say it's more risky than just buying a stable coin (ETH, BTC, LTC etc) and sitting on it for a year (and that's before factoring in the risk of lost potential earnings had you simply bought rather than mined or that your mining pool gets hacked).
After paying off the card (<=4 months of mining) all earnings from mining can be converted to USD for example on a monthly basis. The odds of even 1/10th of major coins switching to PoS in the near future is very low.
I completely agree that just owning coins has way more upside and I suspect you'll do very well! But I prefer the asymetrical mining returns - I have lots of upside and almost zero downside versus extreme upside and extreme downside (crash in coin prices, hacks, regulation, etc.) from owning coins. But to each their own!
So your options there are to either buy ETH on the market, or invest in a miner that will pay itself off in 3 months with ETH, then just provide pure profit for as long as it's, well, profitable.