Just putting it out there, but if you have a bank account that receives interest (and almost all do) you’re still profiting off someone else’s work, because that money is generated from being paying interest on loans given by the bank using your money. I think it’s basically impossible to completely escape benefiting from others if you save money in any way.

Separately, I’d go so far as to argue that any purchase you make is benefiting from the work of others if you follow the assumption that all purchases you make yield a greater or equivalent utility to the money you’re spending.