Perplexity's ad hoc requests are still made by a crawler — whether you believe it or not. A web browser presents the content directly to the user. There may be extensions or features (reader mode) which modify the retrieved content in browser, but Perplexity's summarization feature does not present the content directly to the user in any way.

It honestly just feels like you have no critical thinking when it comes to LLM tech and want to pretend that an autonomous crawler that only retrieves a single page to process it isn't a crawler.

I have used, with permission of the site owner, a crawler to retrieve data from a single URL on a scheduled basis. It is fully automated data retrieval not intended for direct user consumption. THAT is what makes it a crawler. If the page from which I was retrieving the data was included in `/robots.txt`, the site owner would expect that an automated program would not pull the data. Recursiveness is not required to make a web robot. Unattended and/or disconnected requests do.