It needs millions of dollars to launch the product though.

Is that all marketing cost? What exactly makes up the millions of dollars? Because there are bootstrappers that launch successfully by growth hacking, although that is admittedly difficult to do.

I left it intentionally vague for privacy.

That is the money need it to make the product valuable to users. Without it, the product provides 0 value to users. Let's say there are many companies in this space, all spend at least that amount of money to launch.

$0 of these millions is on marketing.

What are you launching, a spaceship with millions of dollars? And how is sharing what your product is a privacy issue? This all really sounds odd to me.

understandable if industry is defense or deep tech, but damn if external funding is their only option to move forward, theyre really fucked.

If you stay on your current course, how and when are those millions going to materialize for your launch?

Since you are competing with existing companies, how are you different enough to be attractive to investors? The fact that you haven't been able to raise any investments to date suggests that those who passed on the opportunity could see things that you are ignoring.