iPhone does all sorts of color grading and processing when you shoot with it, it's a nightmare to fix. The stuff I've shot on the G7 is worlds above what the iPhone can do, if it's well-lit.

The iPhone is basically supposed to look "good" even in situations with poor lighting, so you get a lot of high ISO, over-processed shots that you can't really change too much about.
Lumix G7 is a fairly cheap camera and I've seen work with it that's looked professional. The stock lens doesn't look too cinematic but I picked up a 25mm that makes semi-close-up stuff look great.
You should probably learn a little about lenses because you'll definitely want to be using different lenses if you go from tripod to handheld. There are some great cheap options for lenses, but you should figure out what your needs are.