If YOU recall the point of this debate of english, do tell me.
Read the OP.
No one I'm aware of has posited civilizations that are 50 thousand years old. The first civilizations we are aware of all spring up roughly around the same time as Sumer--roughly 6000 years ago. The earliest writings I can find are 8,000 years old (Chinese). There are potentially older writings.
As to the 50K date, you might be thinking of the emergence of culture. Some hypotheses put the emergence of culture at roughly the same time H. sapiens came into being--180,000 or so years ago. One part of culture is language.
Another thing we can use to push the emergence of language further back is agriculture. Agriculture is about 10,000 years old, and requires communication with the people in your tribes. Without communication, it's difficult to grow crops.
Another thing that pushes the date further back is the tribal society. Tribes have existed far longer than civilization. A key part of tribal organization is communication, which requires language.
Now why can we trust those ideas for dating the emergence of language? You say we need physical writing. I don't think so. Tell me, did Beowulf exist before it was transcribed? How about the tales of the native americans, or the aborigines (who are 90,000 or so years old)? To say they didn't is to be idiotic.
despite that all nations were invading nations - english broke that barrier and came up as the worldly language.
Ever heard the phrase "The Sun Never Sets on the British Empire"? The British empire was the largest empire to date, containing over 36 million square kilometers (14 million square miles).
Next, add the commercial power of the US immediately following WWII.
Coinciding with this is the explosion in accessibility to communication. Suddenly, a person in India can relatively easily talk to someone in the US. Further, those on top set the rules of the game, and for the last 200 years, those on top have spoken English.