"...But time and time again, the community says "Yay, we've invented X, this makes a huge class of security bugs obsolete". Then Y comes along and opens the playing field again..."

To be fair...

This issue exists with every other language as well. I would be very skeptical of any language claiming to be 100% secure.

The same is true of the developer argument. Cyclone, Rust, C#, Java... you name it... they are all capable of producing systems with security vulnerabilities owing to developer quality inconsistencies.