It doesn't display the content type enough, afaik
You can use it to specify which apps are allowed to use WiFi/data, and whether they're allowed to use all the time or only if screen is active. It also allows you to set a hosts file URL and update it with a single click. It has improved my battery life, I rarely see ads (both when using the browser and when using apps), and it force me to use old.reddit.com since reddit.com is blocked by my host file.
It's an excellent app, source code is on github, eventually ended up paying for it. There's far too many apps and system binaries dialing out, it's funny to watch in realtime. What's more amazing is how nothing breaks even when you lock down everything but the few things that need it. Blocking is fine grained and you'll have to scroll through a massive list if you choose to view system apps, but quite happy overall.
Main benefit of the paid option is pcap files. Free version does everything most will want. It's on fdroid.
Useless once you take your phone off WiFi of course, but still baffling the amount of metric abuse going on, and entirely without warning (am within the EU so concerned by it!)
NetGuard is a firewall which allows to allow/block traffic.
Charles proxy only allows you to see which connections are being made. They cannot be blocked, there is no firewall functionality. There is not a single app on the App Store that can behave like a firewall on an iOS device, and Apple would definitely not allow this.
So i personally think he has a point; Apple dictating what you may or may not do with your device, without giving you the possibility to opt-out, is not good. Apples "walled garden" has positive side effects of course, like for example hardly any malware on iOS devices versus a lot of malware/viruses on Android devices.
But still, there should be the ability to opt-out of this when accepting the risks. Without this ability it's much like a dictatorship...