You are right, Investing in Bitcoin by borrowing is not really a good. Because investing with debt, Bitcoin has the potential of not only profit but also loss. Now if you borrow and invest and suffer a loss, how do you repay your debt? According to me, if one has accumulated wealth, then it is better to invest for him.
More precisely, having own capital is much better to invest in Bitcoin than having to borrow money because you want to invest compulsorily in Bitcoin. I also agree with this point because investing with no debt is a very good solution because if someone invests with debt, he will feel two pressures that might not be too difficult to contain.
The first is pressure because he has debt and the second is pressure if he hasn't made a profit but it's time for the debt to be paid off. So in this case I think it's very clear that investing with your own capital, even if it's not big enough, is very much better than with bigger money but obtained by debt.