Yeah, I think this is one of their problems. Their forwards plus Maddison are not very effective at translating territory into actual chances. And then while Son is a world class finisher they have a bunch of other guys with poor track records in that department (Solanke and Werner have drastically underperformed their XG over the course of their careers, Richarlison and Johnson have goal totals just under XG).
In a nutshell, Ange takes huge tactical risks (throwing players aggressively forward, especially the fullbacks) and doubled-edged selection choices (picking fullbacks and midfielders that are very quick and can press like crazy but are relatively small and don't contribute much to box and set piece defending) to get his team into the final third a lot. They can move the ball through the thirds and they can win it back. But they aren't very efficient once they get to the final third because they don't have elite talent in that department any more. And then eventually those tactical risks and double-edged selection choices lead to conceded goals.
There are definitely some parallels to late Wenger era Arsenal.