Should I buy two S19j Pro's for $3,700 USD and mine it for the next few years or just buy $3,700 worth of bitcoin (0.16 BTC) ?
My worry is that mining difficulty will keep going up and I will run out of time being profitable before I reach 0.16 BTC.
At the current difficulty of mining, it will take over 250 days to mine 0.16 BTC with two S19j Pro's (assuming electricity is free) but the difficulty will be WAY higher in the next 250 days...
I love the idea of mining because it allows me to dollar cost average into the market and there is no KYC involved.
Buying bitcoin has less risk than mining because having a miner requires maintenance, which can be more expensive, and power rate changes, but because you stated it's free then it's lucrative. Both mining and buying have various risk tolerances, and it relies on you what is your investment goal.
The only issue I can see with purchasing bitcoin is that it does not directly provide income like mine does.