That depends on your view. The money is created out of nothing, by this vague rule that we can take a fraction to reuse because "there is no way that all people are going to withdraw 100% of their savings at the bank at the same time" so the money is otherwise "just sitting there". Right?

And from the PoV of someone taking on a debt, you have to repay more than you took out, so you have to make that money appear from somewhere, usually by earning it with labor, so yes you could call if "future labor". But they money itself represents someone's time spent, usually normalized by some expectation of efficiency, because they expect you to do the work efficiently to "earn the money".

However, from the PoV of the money, the money represents the time spent. And because the debt is created from the fractionation process, a situation is created where a "larger total amount of money" now represents the "same amount of time" (labor performed). The banks may get the loan repaid at some point in the future. But in the present the money already exists, so *everyone* money has decreased in value.

For the same reason the infamous "trickle-down economics" is insidious. Because even if it "trickles down", the elite can enjoy the benefits of relatively more valuable money *before it trickles down* (if at all).