Unprofitable businesses of every sort don't pay income taxes. Startups like OpenAI don't pay income taxes because they don't have income. And investors don't get a writeoff merely for investing in a nonprofit; it's not like a donation to a nonprofit (which would be deductable).
It feels like there should be a way to tax these startups that exist as vehicles for cash grabs, but are not profitable.
If you literally mean people (as in employees, executives, ect), they already are being taxed on income.
Unprofitable businesses always have expenses for labor, materials, ect. The distinction is that the company and owners arent making money, so they dont pay taxes. Those that do make money naturally do pay taxes.
What is the hard part to square?