I do agree that loaning money to invest solely on crypto is not a great idea. Loans need to be paid on the contract signed. When you invest in crypto, you won't have that assurance that you'll accumulate enough to repay the loan itself.
Crypto may be profitable but unless you take more risk to accumulate more, you would have to wait for the long run by just holding.
That's right, it's not the right decision, other than that doing it will only add to the burden so I don't think borrowing money to invest in crypto is not the top choice,
remember that crypto is very risky so there will always be the possibility of us experiencing losses
You just have to remember that growing your portfolio with the loan needs a recurring income. So lets assume that you took out a loan of 10k, and you need to pay 1k per month for one full year, I am sure 20% interest rates must be valid in some nations or some cases, I know normally it is less but just stick with the example. That means you need to make more than 1k per month with that 10k investment in order to pay it back. The main problem with crypto is that it could turn your 10k into 20k in a single week, it could drop it to 5k in a single day.
So, you may not always be in profit and you may not always be able to sell to cover that fee. It doesn't have a recurring fee that is higher than the interest rate. You could maybe check all those USDT stuff where they pay as much as 10% a year and if your loan rate is lower than you could pay that back, but even in that case you are taking money out to pay hence lowering your return and can't pay it back.