On one of the HF gambling queries. オンラインカジノ (casino online) in Japan since 2014 in the top was a site on the drop domain (or subkey site on the drop). Kept the top for about 2 years.
This was already more than 10 years ago. Drops started to appear actively in the rudiments from about 2018 to 2019.
That's how the anomaly from one segment of the global output came to Ru in about 4-5 years. That's why it's important to look at all geos, not just the target queries where you work. This way you can accidentally stumble upon a working hypothesis.