There is nothing preventing business from running without making a profit as long as they pay any expenses or bonds that are due.
The current tech setup depends on high stock valuations. They issue stock, sell it at a high rate and use that to pay expenses. The sale of stock does not count as net positive in revenue since they are effectively selling a part of their business to investors, making them “owe” their new shareholders equal the amount they gained from them.
As long as investors are interested and the business is growing it’s possible to keep this going for a long time and never pay taxes since they spent everything they gained.
If they are not able to pay their expenses they will have to file for bankruptcy like every other business, whether it’s restructuring bankruptcy, transfer of ownership of dissolution.
So why can’t small businesses do the same? They absolutely can, but the money they get from selling stock is nowhere close. These tech companies are sold sometimes at 20x the revenue where small businesses are likely going to get 20x profit or less.