Overworld corruption

i am delighted that the idea of Nether portals corrupting the Overworld has been around consistently for the almost 9 years i've played Minecraft. however, i would argue that Overworld corruption of the Nether is generally a bigger problem. Overworld blocks tend to accumulate in large quantities around Nether-side portals; in particular semi-shapeless cobblestone structures and excroissances. furthermore, the footprint of each Overworld block in the Nether is 128 times* the footprint of a Nether block in the Overworld.

* calculation: 8× on the X axis, 8× on the Z axis for the usual proportions that we're all familiar with. additionally, i reckoned another 2× since (in 1.16 and older) the natural height of the Nether is 128 while the Overworld build limit is 256.