That one is a little different. That's when Apple clones your app into their OS as a core feature, thereby completely killing your market.

It usually implies Apple deliberately studied your specific app or replicated it based on details revealed in B2B licensing/acquisition meetings, similar to what MS pulled with Stacker back in the 90s.

https://thehustle.co/sherlocking-explained

https://en.wikipedia.org/wiki/Stac_Electronics

Don't even have to go back to the 90s, just recently Microsoft pulled that with AppGet.

Sherlocking is also considered a good thing nowadays. It acts to expand the market by bringing about awareness of such a feature.

Yeah the built-in way is not as good and featureful as dedicated app's but now more people are aware it's a thing and get the app.

Like sleep cycle app is only rising in popularity even though ios has bedtime now.