...What? Please explain why selling t-shirts online is a business where one winner will take all the market share.
Utilities are a natural monopoly. T-shirts are a commodity. There will always be thousands of sites selling them.
Becoming the number 1 player in that market could be profitable if said company could implement innovations that are difficult to replicate by others. But it's not the type of business where a network effect is going to shut out competitors. Customers will go to where they can get the best balance of price, quality, ease of use, and speed.
Spending a lot of VC funding selling dollar bills for 50 cents is not the only strategy, and it risks running out of money before getting to the promised land.
Running a profitable business doesn't mean you can't come to be the best in a market segment either. Profit can be reinvested in the business, and decisions can be made based on what makes sense for a sustainable business.
They have the marketplace and the tooling already, just artificially limiting scale.