When I first stared out in Electronics,all the texts,whether from Australia,The UK,or USA used I=E/R
As English speakers we didn't use European texts.
Later on,there was a gradual change to I=V/R.
I think it was mainly to prevent confusion,as E referred to "Electromotive Force",which had gone out of fashion.
In English,& perhaps other languages there has been a confusion between "V" & "U"over many years.
Old inscriptions often use "V" where modern usage requires "U".
A classic is the letter "W"(" double U"),which is actually written as a "double V".
I always assumed that European use of "U" for voltage came from this,so I just make the mental adjustment & it doesn't bother me.