LOL anyone’s voice should be great through their 40s.
I’m almost 50 and my singing voice is still liked by many people, including my young son.
The reason I mentioned Doris Day’s 1965 and 1967 recording sessions, when she was in her mid forties was because she did not formally record again until the mid 1980’s when her voice was not what it was in the sixties.
Also in context of my posts, I was comparing different versions of “I Remember You” from 1956 to 1965...
Also note the richness in tone in Close Your Eyes in that same timespan.