The Zodiac Ciphers - What do we know, and when do we stop trying to solve them?

Video of David Oranchak talking about the Zodiac ciphers.

https://www.youtube.com/watch?v=BV5R3TBMWJg

I have a theory and it's mine ,it belongs to me and is as follows ,that is to say it is mine alone ,I developed it ,and am the owner of it , ...Ready ?
Brontosauruses are thin at first, then much much thicker in the middle ,then thin again at the end . that is my theory and it's mine


remind me what notable  ciphers he has deciphered again ?   dchek
another theory I have is that sentences having words in them must have a number of vowels in those words
he gives you his info, TMI in my book, then states "of course there are billions of combinations"  .... silly me, here I thought there were only  tens of millions


PS if you look closely at the professor on the far left at the video while Dave is being introduced he's like ...oh lord how did I get stuck hearing this load

Ummm.... ok.

I liked what Dave had to say. I mean, most of it was pretty basic stuff, but I know zero about coding and ciphers and stuff like that so I found it interesting.