There are still quite a few people in different (all ?) parts of the world who now want to go to their own countries. Chris has given one or two examples, there are also British citizens seeking to return to Britain, as evident from occasional calls for the UK government to do something/more about it. That is where these flights still operating come in and, as Chris has pointed out, their mainstay is actually freight. There have been several media items telling of all this, including passenger aircraft being used to carry freight lashed down in the passenger cabin (no passengers) in addition to a full belly. There is currently an enormous demand for freight space because in the past freight formed part of the payload on most scheduled passenger flights - most scheduled passenger flights (reportedly around 90%) mare now grounded, entire fleets of them. This is an unusual situation but none of it is strange, it makes sense if/when you look at it.