Exactly, forest fires usually don't kill most of the trees in an old growth forest. The trees are much bigger, hold a lot more water, and have much thicker fire-resistant bark. This is why you usually see charred parts on the bottom of living old growth trees - they survived fire.

Because the old growth was logged, the fires we have now are often able to kill 100% of the trees in an area because the trees are all small and young and vulnerable. And this is self perpetuating, because after such a fire the soil often erodes, and sun hits the ground directly keeping it dry - it takes a really long time to recover from in some places.

Each cycle of logging removes even more soil and makes the landscape drier, and resets the timer on how long it will be before the forest is able to survive a wildfire. It's a short term thing.

I'm not saying no one should ever cut a tree or use wood - and it can be done in better and worse ways, it's really complex. But in general, the repeated clearcutting of the pacific northwest is steadily degrading that landscape the same way repeated intensive till farming of the prairies is degrading that landscape - it's a relatively short term thing with diminishing returns.