Well, first off, because the Angles, Saxons, and Jutes only invaded the British Isles after the Western Roman Empire fell, second off because it was never a Latin culture outside of certain cities it was still, broadly speaking, Celtic and would remain so through several more waves of Sea Germans and their dubious understandings of consent, property ownership, and human kindness.

Also, it's not just "Anglia," Angle tribal territory was a pretty significant portion of Jutland, that peninsula region it's part of.

Speaking of which, as mentioned before, the Saxons and Jutes, the other tribes on the peninsula, also invaded with the Angles so that whole damn idea of "Anglo culture" deriving from Anglia alone is just agenda driven revisionism.

Hell, what about the Norman invasion? Norman, aka Frenchified Viking culture, was just as impactful on what became English culture, and Rollo's crew of ne'er-do-wells were largely recruited in Norway prior to conquering the northern French coast.

And let's not even get STARTED on Latin culture apparently having no cultural impact through the majority of the eastern Roman empire, including Greece and Anatolia, despite the Eastern Roman Empire only falling in 1453.

Like, are you fucking seriously not going to give the Byzantines a nod while you pretend Romania is a Latin culture?

I SPIT ON THIS MAP

Well the vibe is still broadly correct tho. Replace "Anglia" with just, you know, England, and it's better, even if it's hilariously Eurocentric. I realize the maker broadly wanted a global cultural impact map but that notably shortchanges at least the Arabs and the Mongolians and/or Turkic peoples in the map painting departments.