But where do you find it? Almost the entirety of internet is UTF-8. You can always transcode to Latin 1 for testing purposes, but that raises the question of practical benefits of this algorithm.

Older corpora are probably still in Latin-1 or some variant. That could include decades of news paper publications.

All of Europe has written in Latin 1 for a decade. There are billion of files encoded in Latin 1 everywhere.

Where?