Well it is hard to play what ifs here because, for example, several ADs are able to effectively play their lane without needing mana. Also stuff like Ez, Ashe, Cait, later on Trist, can harass a Blitz. Blitz is a good champion and all but there are many characters who don't need a lot of mana to avoid harassment and stuff like Trist/Corki/Graves can troll a Blitz's grab.
From my experience if that brush is warded Blitz is done.
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"What I'm saying is mind over matter only works when there's not much of a matter to mind. " - Lopen
The Cult of Personality.