The west coast has large tracts of unoccupied, I maintained forest land, and a more Mediterranean climate (wet then much drier).
The two combine into large, periodic forest
Fires.
The east coast has much fewer unbroken tracts of forest, and where it does have them they are more heavily managed and stewarded for a number of reasons.
The east coast was developed and property subdivided/allocated long before the tendency towards large national parks, monuments, etc.
It isn’t that these national parks or forests cause all these problems (though many of them DO feature prominently in these huge fires), they are also a sign of the very different nature of land allocation during the settling of the area.
You can see this pretty clearly if you pull up maps of federal land (national forests, national parks, blm land, etc). Several western states have more land owned by the federal government than anyone else.
They are all out west.