I wouldn't go so far as it is some sort of a planned invasion ..but I think the reason for modern migration is people moving for better life to the west .. which they have the right to do because borders are unnatural imposition ..
The proof is in data .. how many people say for example moving to US v/s moving away from US to other places ..
Which means if most of the people aren't pushed to leave their homes just to make survival money , they would choose to stay in their homeland with friends and family and the weather they are used to ..
There will still be explorers and tourists .. and they are always welcome everywhere ..
Bitcoin fixes this , because with hard money in their stash , everyone has a fighting chance where ever they live.
Mass migration has always been due to some catastrophic event .. in our case it is economic disparity. Thus our current migration pattern is unnatural!