You are missing the core idea. The destruction loss is measured is terms of value of produced goods so it only makes sense to compare it to the final value of produced goods. You can’t compare destruction of finished goods to that of raw resources collected; that is like comparing apples and pears.
Collectively, we keep 2/3rds of what we build each month (ignoring loss to people quitting) and thus get richer and richer.
The ISK leaving the game is in this chart:
https://images.ctfassets.net/7lhcm73ukv5p/1lPXBY3HzywKUqW8UKSI8q/b7b81983bb5417807c05c0352f0fbc82/9a_sinksfaucets.png
It’s the active ISK delta there. ISK lost to people quitting the game in March was almost half of the ISK taken out of the economy by all the ISK sinks in the game. It is not insignificant.