Borrowing is effectively gearing the results.
If the borrowing is affordable, and can be employed to create more wealth than the total cost of the debt, it is beneficial, PROVIDED THAT it does not also make you more vulnerable.
Unfortunately, it is the vulnerability that usually sinks people.
For example, suppose I decide to buy a £500,000 house on a 100% mortgage, interest-only : the repayments will be lower initially than those of a repayment mortgage, but because I never build up any equity in the property until I find a separate source of the £500,000 I risk losing everything if I fall behind with my interest payments.
If I have instead a repayment mortgage, I may need to reduce my total loan to take account of the higher repayments, but gradually I shall build up enough equity to own the house - or if things go wrong, I have a lower sum to find elsewhere to meet my commitments.
But ALL gearing like this, whether interest-only or repayment, is risky. If it works out, you can gain handsomely; if it doesn't work out, you can lose more than if you had taken it gradually. You can be wiped out.
Those with negative equity on their house will tell you how utterly miserable it is being trapped, with no clear way out.
Better to buy only what you can afford easily - not overdo the gearing.