Social Media vs SEO Traffic

What do you think is more sustainable in the long run?
Whats the better ROI?
Whats more work in less/more competitive niches?

Generally, SEO traffic is higher quality, mostly because the user is actively searching for something. Social media traffic is a passive type of user, so they aren't actively looking to buy or sign up for something. That being said, there is plenty of money to be made with both types of traffic, and social traffic tends to be cheap, so there's that as well.

Every time I hit page #1 on Google.

My sales increase 200%-500%!

We can't denied how "golden" Google organic traffic is.

Compare to social media traffic, the conversion rate is too low. Really low.