Why do adults treat us like we’re still 5 year olds?

So some adults treat me and my friends like we are still little kids even though we are all 12-14 years old! We are more advanced in some ways like with political beliefs, personalities, empathy and emotions, and news, most will use the fact that we still watch “kids shows” like The Amazing Digital Circus, and kids YouTubers. It pisses me the F*K off! And then they have the audacity to take our privacy, and limit our ability to communicate by taking and looking through our phones and computers without any warning or reason!