4 years of development and they didnt have anything to show except for a CG render?

Anything to show you. They aren’t beholden to you. The CG render was to get applications for jobs, not to sell the game. That happens when it’s almost done.

Are there any examples of games which have had 4 straight years of radios silence that have not had major development problems?

The vast majority! Game dev cycles are often 8+ years now, and you don’t hear anything from them until about a year before launch. You think about the canceled ones, but most of them that launch you just don’t consider, which is good. No news is good news, as the saying goes.