I agree, with @DaveT It still stands out to much for me also. Consider this screenshot that shows how on completed items the emails “blend in” with the completed, but the date text still being black makes it “jump out”.
Related (but off topic for this particular thread) - I’d love the option to grey out TAGS in completed items as well. I often keep completed items in view as they help me track where I am in various projects, etc. But I really do want ALL parts of them to be very obviously COMPLETED and not visually mixed with active items.)