It feels nice for someone to agree with you. As social animals, we get some sense of nice feelings when this happens to us. However, having too much of one thing will almost always turn out to be a bad thing. Such a case is having an overabundance of people that agree with each other and reject criticism, otherwise known as an echo chamber. 

Echo chambers isn’t a literal term, but rather one used to describe an environment where people will continuously regurgitate the same opinion or opinions with each other. This has been normalized on the internet as its extensive reach allows Echo chambers to form much easier as similar people gravitate to similar topics. Phrased this way, it sort of sounds like just another group. However, it is not. As a healthy community builds itself up and encourages communication, and a community that is an echo chamber is detrimental to communication and new things.

Echo chambers can easily lead people to believe misleading or false information, as they will stop questioning things because they have come to trust those in a leading position. Their alliance with a group gives them more leniency; and if no one questions it, they may come to believe it and even spread it. 

What I’m saying is that: it is somewhat hard to notice an echo chamber from the inside of it, and you should take care to observe before joining a group. I do have personal experience with being in one and the rather close-mindedness that comes with it. And I urge you to also check the current groups you are a part of and, perhaps, cut yourself off before you come to be completely subservient to them.