This is, indeed, the fast track to a return, though if you’re just active enough to mine the most profitable coin and flip it to BTC, mining is much lower risk once ROI is reached on hardware, plus it’s a bit more passive than trading (checking trends all the time).
Here’s a decent example:
I bought about $820 worth of crypto over the last couple months. I just sold it, and got about $950 back. If I put that $800 into a mining rig, I’d still be net negative on hardware costs, but I’d have generated more than $100 worth of coin. In a couple more months, it’d be paid off, and would continue slowly becoming more and more profitable, without me really doing anything. Instead, I have all my cash back, but now have to reinvest it anyway if I want it to continue to work for me. You know… risk and return.
If you’re talking about putting several thousand into trading, then yes, it’s way more profitable than mining, but again, higher risk.