There are many proofs. But some people are too blind or too proud to see them. You can check out provingislam.com for a teaser.

That's as scientific as a Marvel Comic Con. That just tries to align with your bias, there isn't any science on it.

It is scientific, just not experimental science which is limited. Look up Islam's Isnad system to learn more. There is nothing like it in any other tradition, faith or historic or otherwise. If you only follow experimental science, then you follow the religion of scientism, which only give a partial picture, and sometimes even an incorrect picture.