I think this is dangerous thinking, lies are bad but censorship is worse because someone has to decide what is a lie and what isn't, and that quickly becomes politicised. That never works out well. Since you mention Turkey, look at the current government's suppression of journalism. Freedom of expression must be protected as a legal right to maintain democracy.
On the other hand, freedom of expression includes the freedom not to facilitate other people's speech if you choose. I fully support the Parler people's right to propagate whatever bullshit they like as long as it isn't planning or inciting crimes. Equally I completely support Twitter, Facebook, AWS, etc's right to choose what they do and do not allow on their platforms. That's freedom too.
This is all part of the process of civil discourse. However uncivil it might seem right now, it's something we all need to work out as free citizens.
My way of thinking is that if someone mentions(even implies or dog whistles) someone else on a social network, the person subjected to the words should have an automatic right for a visible reply. A reply that everyone exposed to the original text is also exposed. Expand it to issues too. If there is an issue, let's say global warming or geology, the flat Earthers should be able to post a visible statement under the photo of Earth posted by NASA and climate scientists should be able to post a statement to climate change deniers content.
BTW, the media situation in Turkey is much more complicated than your mental model of censorship. The media is controlled through money, essentially the media owners get lucrative government contracts if they play nice with the government(an audio recording of a few real estate developers with connections to Erdogan discussing creation of a capital pool to buy out all the mainstream media was leaked. They bought all of it anyway and got into TOP10 contract winning firms in the world [0]) and the radicalised ones that only few care about are left alone as long as their reach is limited to the radicals. The police isn't chasing journalist as much as main stream journalism becoming non-existent and simply being a negotiation tool for people who fight for power. There's a new hope with Youtube journalism becoming mainstream but of course just recently Google was forced to create a local office to moderate the Turkish content. The government introduced advertisement ban on media that doesn't have a local office to respond to government requests.
[0] https://ipa.news/2018/12/30/turkeys-pro-government-construct...
Thing is first step would be to teach people again critical thinking and what the difference is between objective facts and opinions. Furthermore, something I am missing in this discussion and in general is that the concept of responsibility is lost. Sure you are allowed to say anything you like, but that does not mean there are no consequences.
In the analog world we have libel laws and some limitations on speech ( incite violence, endanger others ). For example in Germany it is straight up illegal to deny the holocaust. We as a society have decided that this is the correct decision for that instance to ensure that it won't repeat itself in some form or another in the future.
Other 'speech' laws in germany make verbally insulting others fineable, because human dignity is the fundamental principle of the German constitution. Article 1, paragraph 1 reads: "Human dignity is inviolable. To respect and protect it is the duty of all state authority." Human dignity is thus mentioned even before the right to life.
Anyways what I am trying to say is that just as in chemistry actions will have reactions. Therefore, speech should have consequences. Ironically, republicans have preached over the years that everybody should be responsible for themselves and their actions, and not rely on others but when it is about consequences of speech they are silent.
What we need is a mechanism for breaking circuits of lies and propaganda. In real world social networks we have methods like labelling liars(You have one identity and you risk it every time you say something), right to defend yourself(You can actually identify and force your way to reach the people who are exposed to, or facilitate it) if you are being smeared for or accused of wrongdoing. You don't have these mechanism in the digitalised version of social networks. Social networks work like cults, your reply to an online mob at Twitter/Instagram/Reddit/FB etc. reaches no one else but your own cult(if you have one).
Oh and believe me, lies are dangerous. In istanbul there are many abandoned beautiful buildings in central locations, many these belong to Greeks who lived in Istanbul for generations but in 1955 were targeted by the Turks who were told by a newspaper that the Greeks bombed the Turkish consulate and Ataturk's birth house in Greece: https://en.wikipedia.org/wiki/Istanbul_pogrom
There was nothing centralised about this Progom, the newspaper was not the governments publication like in a Communist dictatorship. Yet, it caused so much pain to the Greek minority and Turkey lost so much as the Greek christian population declined from 120K to 7K in 20 years.
If anything, decentralised networks can be targeted very efficiently by a bad actor and the rest would have no recourse. There's nothing stoping (fascists/communits/liberals/$_YOURBOOGYMAN) to identify decentralised networks, connect to all of them, participate and run a propaganda campaign through a centralised unit that connects to all the decentralised networks.
If there were thousands of decentralised social networks, QAnon could have used Buffer to manage their presence in all of them.