Passé Composée use here

Paul, 

it is still true, so passé composé is used. The use of ‘toujours’ is relevant here.

This is an ‘advanced’ case usage of passé composé - see link to some past discussion, and links from within the discussion to other material. 

As this is something happening and true in past and in the present, passé composé is required.

Imparfait in its past tense usage only describes events that were completely in the past, notwithstanding that they may have been ‘ ongoing ‘ or ‘ habitual ‘ then and had vague onset and completion, they are not habitual or ongoing ‘ now ‘.

 https://french.kwiziq.com/questions/view/passe-compose-or-imparfait-1