It depends.
I prefer Woocommerce for diferent reasons, it's more flexible, it has more plugins, and easy to develop plugins for it.
The problem could be a lot of products with variations... it needed a lighter theme and less plugins...
For SEO is perfect with an optimal SEO-ON Page.
Prestashop was a perfect shopping for security and light weight... but for SEO is less than Woocommerce.
Shopify it's for begginers basically, although it has a plenty of extras, but if you need more... go to Woocommerce or Prestashop
It's my opinon...