[livueta]

Afaik, while better anti-tank weapons did come about during the war, a lot of it was also to do with adapting tactics and usage of existing weapons to counter the new "meta". For example, the flak 88 and the 90mm M1 were originally intended for use as antiaircraft weapons and were widely deployed as early as 1936-38. They just so happened to also be excellent antitank weapons, once people figured out how to deploy them as such.