This happens all the time. The difficulty goes up, the price goes up. The price goes up, the difficulty goes up. Hashrate goes up, the price and difficulty both go up.
You don't mine to earn dollars, you mine them to earn bitcoin. Don't pay attention to roi calculators. Just know that you have a machine that makes btc for you and you got it at a set price. You run that machine at a set price, too, but the bitcoin price keeps going up. Don't worry about what the coins you mine today are worth today. Think about what they might be worth next year.
Well, i should agree to this. Because once we mine today it will not cost as like what it will be cost on the future, when mining, always think for the better future and think for the price of a bitcoin in the near future. If bitcoin price today is $6500 then think of that bitcoin price will increase up to $10k or more.
I also do not always pay attention to ROI, as long as I can do the maintenance system then one year is not an important time to get the initial capital, the ever-changing difference with the harder blocks makes the system stronger, it will extend the mining time. What we need to consider is the system of care and regulation on a regular basis.