Thanks for the tip. Fotografiapuntoit shared a video on YouTube that shows the impressing capabilities of Canon’s 250MP sensor. The video has English text.
A 800mm telephoto lens was used. The advertising on a hotel can be read with the 800mm from 15km distance. What’s interesting is a Canon technology called “turbulence removal”, i.e. it can stabilise the “fata morgana” effect you have when zooming on long distances. You can see “turbulence removal” from minute 2:04 on.