Earlier quoted context omitted.
> Colonial conquest is not the primary methodology of linguistic propagation. Trade is. A "primary methodology" only applies in "most" cases, not all of them. Lots of languages have perished for outside forces other than trade -- the Hebrew wasn't abandoned because a better trade language came around, but because Israel was conquered and the locals scattered. Other languages were persecuted by decree. Others died bec…
Aramaic was the primary language of trade for the first civilizations during their initial rise. As other trade empires blossomed, more languages appeared, and as trade empires collapsed, those languages vanished. Religion can and does preserve memes and linguistics, but only trade can scale it out.
If it was just for trade, language learning would be relegated to merchants in those countries and few others.
Government, bureaucracy and occupation matters more than trade in this regard. That's how latin become the norm in a large area during the roman empire -- and not because everybody in those regions traded directly with Romans or couldn't agree on pricing otherwise.
Same e.g. for French -- it's not because of trade they got big as a language in the 18-early 20th centuries, but because the french run a big colonial empire.
And English, beyond trade, were the language of the big British colonial empire, and afterwards of the dominant culturally power that was America (Hollywood, rock, pop culture etc.).