Not nearly as easy as people seem to think it is and it is beginning to get incredibly saturated. There is a store for nearly everything and the competition is ridiculous because of it. The most difficult part is getting your store noticed, which costs a fair amount of money if you're going through facebook ads, etc. Word of mouth is the best way to get customers but it's difficult to start something like that.
I still have a Shopify/Dropshipping store, so if you have any questions let me know. I'm not willing to share what the site is, so don't ask for a link. The store is for home decor targeted at college-aged individuals, and people who are looking to add to their smoking or trip rooms.