You usually can make a prototype of literally anything with less than $10K. Education on the internet is free. And the internet itself is free at any Starbucks.
The cost of your unpaid time is often the most expensive thing.
Your time in Starbucks costs, at least, the sum of your home's rent or mortgage, food, and the laptop and phone you are using (and their occasional replacements when they break).
That can easily reach $10k by the time you've made a convincing prototype.
So giving millions to people who are already privileged enough to have access to the tools/resources/education to make to a prototype?