It’s certainly not feasible to hit all the trees this way, absolutely not. And while there have been projects moderately successful at eradicating insect problems, I don’t really know of any for funguses (not saying they don’t exist, I just haven’t heard of them).

But most trees species have some kind of systemic pest problem, yet here they are. Every so often we lose the vast majority of a given species in a given area, though, so it’s really hard to say at this point whether oaks are gonna go the way of the chestnut, or whether they’re just having a couple extra problems at the moment.