They have the same general concept. Depending on what you're aiming for is the challenge. I'd say that electric is easy but it costs money to get the right equipment.... acoustic calls for more talent and creativity because you can do more barebones dry with an acoustic guitar than you can with an electric guitar and just 1 amp.
In my honest opinion, I'd say acoustic is harder, but sounds way more beautiful. Like i said, electric guitar cost a lot of money. If you can get a great grasp on acoustic guitar, you can do even way better on electric than people who start off with electric guitar. Talent won't always come easy, and if you just want to get into something expecting for it to be easy, then you'll just be less than mediocre and not necessarily satisfying anybody....not even yourself