You said you can't buy that he never gets chances and that he should have had at least 20 goals. I hadnt said he doesnt get chances, but that with a better midfield, the chances are he would score more. Would you prefer someone like Gabriel jesus? His shot to goal ratio was worse than DCL. Or Firmino? Who only scored 9% of his shots. They get way more chances than DCL yet his shot to goal ratio was higher. He had higher shot success than salah as well. Even the players at the top who are apparently much more clinical miss loads. (More than dcl).
Go on then, name them. You realise only 4 players scored over 20 last season. There's usually only 3/4 most seasons, 20 goal a season strikers are very hard to come by (unless you are one of the top 3/4 or get lucky).