The Reason behind using Multi-Page form : Multi-page forms is to make sure you get higher qualified leads filling out your form. By forcing people to go through multiple steps to convert, you know only those really interested in what you have to offer will finish.
After all, it doesn’t matter how many people complete your site’s form if they don’t turn out to be the kind of person you’re looking for.
More leads don’t mean more sales. Qualified leads mean more sales.