Maybe also for "Pages" and "Page title" report if only one directory given. Or to describe it in general: If only one row on a certain level is given, it might make sense to expand this one automatically.

See for example following screenshot:

It's kinda obvious that my next click will be to expand that domain and it will look like this:

Ignore the broken characters this is because of testing #7866.

For pages, if there is only one first level and one second level row, we could maybe even expand the first and second row automatically.

There's one disadvantage: It makes it a bit harder to see whether are downloads / outlinks / ... from multiple domains. Eg imagine there would be 50 different outlinks under example.org and it would not fit into one screen when automatically expanded. So it is not directly possible to see whether there's a second domain further down. But I think the advantages would overweigh the disadvantage and people might notice if the table is expanded automatically, that there won't be a second first level row (it's hard to learn this behaviour as a user though I reckon).

For many users that have eg downloads only from one domain or all pages under a certain directory it must be very annoying to always open them to see the stats.

I've seen this behaviour in many products. For example PHPstorm would automatically open all folders if there is only one folder/file in it.