The Germans come up with the dogma of the assault gun or "Sturmgeschütz" (in German) and they had stugs serve in artillery units.
Here is also the Wikipedia article:
"An assault gun is a form of self-propelled artillery[1] which uses an infantry support gun mounted on a motorized chassis, normally an armored fighting vehicle.[2]"
You should read the whole article instead of picking the parts you like. The article literally gives examples of stug 3s as replacing tanks:
"Battalions of assault guns, usually StuG IIIs, commonly replaced the intended panzer battalion in the German panzergrenadier divisions due to the chronic shortage of tanks, and were sometimes used as makeshifts even in the panzer divisions.[10]"
Now do actually have a point?
Yes, I made it very clearly for you. Assault guns were not
only used for long range artillery. It wasn't even their main role
Suggesting otherwise is completely false, even based on your own source