After 2.Bxb5?! axb5 the weak pawn on c2 and the entry square on c4 are more relevant factors than the doubled b-pawns.
This sacrifice is hardly any correct, but White was short of active plans.
Intending Bh4-g3 to swap Black's good bishop and prevent the ...Nh5-f4 manoeuvre. The bishop transfer to g3 is indeed a common idea in this French structure.
Preparing ...Kh7 and ...Bh6 in order to swap the "bad" bishop for the "good" one.