For everyone looking for a business that has no loss, if this business really existed, everyone would have entered it and left everything else. However, at the beginning of every business, people convince themselves that loss is impossible and profit is guaranteed.
Any business should be calculated correctly, not based on dreams that many build their hopes on. So, if you write a feasibility study for your business and find no percentage of loss, then you have to rewrite it. Sometimes the loss is time, not money, and this applies to services more than products.
There are many ways to reduce losses. You should start in the smallest way possible in the first period + you should know the need before expanding the business. The smaller the business, the smaller the losses.