In great cathedrals of the past, the high altar was not necessarily visible to all. The choir stalls in front of it, sometimes a rood screen or other piece blocked the view. Lesson and Gospel were chanted and could be heard. The canon was silent. A bell rung at offertory, sanctus, consecration and communion made known where the action was at any moment.
Matters are quite otherwise today.
All is open, visible, vocal and intelligible. And like Jesus on the cross, the priest faces us and prays in our tongue. Perhaps we need no purple curtain to remind us that sin interrupts converse with God. The world around us is a message clear enough. Nor must we once again make a litany of the woes of our dreadful time.