The world we live in is increasingly controlled by corporations and governments, sometimes working together, and the individual is left with less options to deal peer to peer and more middlemen with any online interactions. Decentralization allows for individuals to connect directly to others for needed services and is often censorship-free and the network itself becomes very difficult to shut down. Apps like BitTorrent have been around for a long time now and while the users can easily be tracked it still makes for a very strong network that can't be stopped.
In more recent years, people have started taking notice of the importance of freedom from online censorship and since the beginning of bitcoin many apps have been built around this technology that allows for that freedom. Bitcoin itself offers a decentralized platform for transferring value between people. Other use cases involve decentralized file-sharing like IPFS or decentralized internet being pioneered by apps like Zeronet, Maidsafe, and BlockStack.
Companies like Facebook or Google continuously data mine our activity and store it on their servers or even cooperate with governments by giving them access to messages, emails, and anything else they demand. Putting so much trust and access to our private online activity into the hands of these companies grants them enormous amounts of power over the individual. You'll hear that "You have nothing to worry about if you have nothing to hide", but is that really the case?
Throughout history governments have used opposing political viewpoints or distaste for the ruling class as means for arrest or even execution. You might follow the wrong page or join the wrong forum and today it may only result in a ban from that platform but in the future it could mean a monetary fine, or even jail time. People like Edward Snowden and Julian Assange are prime examples of how governments treat people that oppose them and have the means of really influencing public opinion.
Along with decentralization, privacy is an important aspect of online life that we need to consider moving forward with these technologies if we want to remain free and able to discuss ideas without risk of government intervention.
Thank you for reading.