Windshield is contaminated with all kinds of pollutants. Almost everything comes off with regular car wash.
But silicone residues will not. Yes, there are some wiper blades with silicone in their compound. All silicones
are not the same so wiper made out of silicone is not made out of same silicone smudge on the glass surface
It is recommended to waste 30 seconds every week to clean windshield wiper blades while cleaning vehicle.
I wouldn't go hard-core with silicone remover every week. Usually (in my climate and roads) glass tends to be
streak free for 1-3 months after silicone removal process.