We're also up against a century of planting trees at 2x natural density after logging. Logging can be a useful management tool, but if we plant 2 trees for everyone we cut we're not building healthy forests, and we're just increasing fuel loads.
Meanwhile, climate change gets most of the press. Yes it is a contributing issue, but it's unfortunately being used to absolve the forest managers of accountability.
A good read is "The Big Burn" by Timothy Egan. It details how at its founding, the Forest Service knew the fire suppression regime they were creating was unhealthy. But it was the only politically possible path for them at the time.