SasuSaku fan's wouldn't really exist if Sasuke wasn't good looking.
If we are being honest, the pairing is incredibly superficial. God knows if someone treated you, your daughter, or any female you know like how Sasuke treated Sakura, they wouldn't conform to that type of relationship. Though I'm not just blaming Sasuke, Sakura's obsessive nature of Sasuke isn't entirely humane for her person either.
Would of been better for Sakura and Sasuke if they just never got together. Either way to answer your question, it would be mixed. Good looking characters always have a fan base of girls (and guys who self insert) themselves into some kind of equation. That isn't always bad ... You see a bad-ass character, and you want to see yourself in those shoes.
I don't think Sasuke would have been as popular, especially not with his over exaggerated character development in a bland series. Not the best character of the series in my opinion, I would firmly rank him below Jiraiya at best. His fan's wank him too hard, though I don't set my limits of characters from just Manga.
Let's be real, Sasuke always has been the 'cool guy, mysterious, bad ass, genius, and good looking male character'
If you remove any of those components, it just won't be Sasuke anymore. There will be a falling out of some kind.
Personally, I think the main two reasons why I think a lot of people like Sasuke are horrible. These are:
Appearance
His bad attitude/ rudeness to people when he was a kid/teenager
This is not to say that there are no good reasons to like Sasuke. After all:
His power is epic and he has one of the best move sets in the series.
His battles are epic and entertaining.
He's analytical in battle.
His overall ideology is great (starting with his revolution phase and continuing on to adult Sasuke's attitude), but it still had some kinks.
He is a dynamic character.
All of the above reasons are good reasons in my opinion, but I just find it so annoying how people seem to glorify "edginess" and see it as so cool. Usually the edgy characters that I see are just stupid a** holes who treat random people like crap and bring anger, pain and misery to people for no justifiable reason. Most of the time even their own internal conflict is just plain pathetic or stupid! Just look at some of the "edgy" characters in this manga:
Indra Otsutsuki: "Wah wah boo hoo, Daddy didn't choose me to teach ninshuu, so I am going to start a war with my brother that will last for centuries and take countless innocent lives (even though if I were a logical person I'd realize that I could actually still teach people ninshuu even without being chosen by Hagoromo as the successor)".
Boruto Uzumaki: "Wah wah, Daddy won't play with me 24/7. I know he is literally the leader of the whole village and I also know that I am freaking 11 or 12 years old and too freaking old to be obsessing over play time with Daddy, but I don't give a crap about the needs of villagers! I want to play hide and seek right now!"
Do you see what I mean here? There are a few edgy characters who are cool such as Madara, Obito, and Nagato who truly wanted to create eternal peace. However, many edgy characters I just find to be stupid and whiny! I don't see what is so cool about them.