Why did they phase out the Pak 38 so quickly?

>>34821311
Even thought the gun offered pretty respectable armor penetration and was largely successful early in the war, as russian vehicles grew over the course of the war the pak 38 was no longer sufficent to defeat frontal armor on soviet some red army vehicles. Hence it was replaced (read as: supplemented) by the pak 40

File: Pak 43.jpg (351KB, 1471x753px) Image search: [Google]

351KB, 1471x753px

>>34821345
How about the Pak 43? It seems too big to have been useful if Germany ever went on the offensive again.

>>34821377
You've just explained the entire WW2 towed AT gun problem: As guns got larger, they got inherently less mobile and more difficult to emplace. Not as bad in a defensive posture, but providing AT fires when on the offense becomes more challenging with large towed guns.