To be fair, after iMovie's controversial rewrite and re-design in 2007, with each new version some more features found in pre-2007 iMovie versions were added back in, along with some neat new features. This was especially noticeable with iMovie '11's release in fall 2010, when it brought back the detailed audio editing features (i.e. waveforms, "rubberband" volume level control, equalizer and audio effects). The current iMovie still has those features included, but it still has some limitations, like still being able to work with only two video tracks and at least ten audio tracks, no control over video effects, being able to only work in 16:9 (you can work with 4:3 video but it'll be pillarboxed if you choose to not crop it), no DVD chapter marks, and fewer export options. But I still tend to often use the current iMovie for my fursuit vlogs and for simpler videos, otherwise I'll use Cyberlink PowerDirector of Apple Final Cut Pro (the latter I exclusively use for my YTPs).
That brings up another point; when you're ready to go beyond iMovie but are not ready for Final Cut Pro or DaVinci Resolve or Adobe Premiere Pro, there are a few affordable consumer options available for the Mac, including Adobe Premiere Elements, Cyberlink PowerDirector, and NCH VideoPad Professional. You get excellent multitrack audio-video editing and a little more than half of the features available in Final Cut and Premiere Pro. It's kind of similar how with Windows, many start out with the (more limited than iMovie) Windows Movie Maker and then move up to PowerDirector or Premiere Elements, or other similar Windows-only options like Magix Movie Studio or Nero Video or Pinnacle Studio. For prosumer/professional use, DaVinci Resolve and Premiere Pro also work on Windows, but to take the place of the Mac-only FCP, you could use the Windows-only Magix Vegas Pro or something. (I've often referred to Final Cut Pro's recent versions as being like Apple's version of Vegas Pro.)