I understand, I wen through the same process. It is really easily bypassed if your provide minimum effort (ie: you only use the app for a few minutes), but then again you could provide more effort and upload custom hosts files or something. In any case, you won't ever have such fine control over your traffic as when you use this app. However, the important thing is you do not view it as an all-in-one protection. It all depends on your threat model in the end. Do you want to think about this kind of stuff? Or do you trust the app you use to only use network when you want them to? Personally, I choose to chill out and have a quiet mind over avoiding some traffic between Facebook and Spotify. It still bothers me, but I prefer to just avoid Spotifiy as much as possible. To each their own!