Gonna guess you don’t handle the monthly bills for your business. This thinking does not apply to real world applications.

It's not about being greater than zero. It's about being greater than the price you can buy it at or sell it for. It doesn't make sense to spend more time and effort to build something you can buy for much cheaper. Especially if that something is fungable. I get spending $150 omln fabric and other materials to sew a dress that you can buy for $30 because then at least you have a unique dress. Bitcoin is the same whether you buy or mine in.