When they started it was mostly a styling thing, think like Toyota copycatting the Dodge Charger front profile. The big tradeoff was "but muh fuel economy" and those people got over-ruled. And now 10-20yr later the industry has adapted and optimized for them in the form of utilizing them for crash purposes (and big cooling systems). The safety people consider them integral and so they can't be gotten rid of and the aerodynamics people are no longer whining so hard because they've spent the years figuring out how to somewhat mitigate them.

I think in an alternative universe where none of that happened we likely would have invested the R&D elsewhere and found creative ways to get the same results (you can see inklings of this like the airbag style hood lift thing) with much lower more aerodynamics and visibility friendly hood lines.

But that's just my opinion from being on the fringes of the industry.