Honestly, I grabbed a cheap one for a beach trip last year and it was perfect. My phone stays safe and dry in the bag, but I could clip the cam to my hat or just hold it in the waves. The video isn't movie quality, but it caught my kid's face when a wave knocked him over... that genuine laugh is priceless. For thirty bucks, I got clips I actually go back and watch, which my phone footage just sits there forgotten.
Yeah the "another thing to charge" bit is real... but it changes how you use it. I'd never hold my phone out on a bike trail or near spray on a boat, but with a cheap cam I'll just clip it on and forget it. The battery lasts for a full day out, and the clips are so short I only really have to charge it once a week if I'm using it a lot.