CDG was a leading airport when it was completed about 40 years ago. Since then it has been far surpassed by hundreds of others round the world and is possibly the worst of all the major hubs in Europe. It's badly designed, disjointed, impractical, ugly, and staffed by some of the rudest airline staff on earth. It also has the worst and most expensive eating facilities of any major airport and the surliest immigration staff. Despite the fact that AF-AF connections are usually maintained, it's the Achilles Heel of AF and the reason I avoid flying on AF.
AF itself, in the air, is not a bad airline. CC are variable but generally efficient and accommodating, if a little lacking in warmth, and the food is better than a lot of other longhaul carriers.