I don't think anyone mentioned crawling (in my mind, "crawling" refers to a long-running process over several pages or sites and "scraping" could be a single fetch of a single URI)

I'm sure there are others, just from the top of my head:

* Electricity prices (as OP mentioned). Especially for people with solar panels or multiple options for heating.

* Watching for availability/prices of products or new homes one might be on the lookout for. Notifications at price drops/availability

* Public transport: next bus/trains from closest station, delays and interruptions

* IMDB/tvdb/etc for monitored shows and movies. Common with sonarr.

* Air quality, covid outbreaks, whatnot

Some people have smart mirrors or any other kind of 'news display', so it may be useful for them to scrape the data they may think relevant (this may be weather data, stocks, or even the new Nintendo Switch availability at their nearby retailer).