Since we don't have a tea culture I don't know that it's possible to generalize European tea in any way. Feels like half the time when I ask for tea someone pulls out a box with a bunch of aromatic leaves but literally not a single tea leaf (not exaggerating, I've had to drink some herbal mix because I didn't want to be impolite). If they do have some actual tea, it's either litpon yellow (tasteless and inoffensive) or English Breakfast/Earl Gray (actual proper tea that I suppose you could mix milk in just fine).

Habitual tea drinkers such as myself do have the good stuff though, aromatic or not, and we don't put milk in it. That behavior eludes me, if you don't like the taste but want caffeine just drink coffee and milk, and if you do like the taste why dilute it with some hyper-caloric stuff? I posit that's what makes British tea culture, y'all put milk in your black tea because you don't like the strong taste but still you drink it for cultural reasons.