Yes… one of the great myths of fundraising is that VCs invest in “ideas on the back of a napkin.” I even wrote an article about it:

https://aarondinin.medium.com/the-fundraising-myth-entrepreneurs-need-to-stop-believing-ae607c78b2b2

The only way VCs would invest in an idea on the back of a napkin is if someone like Jeff Bezos was the entrepreneur.