Fallout 4 ending what is better?

Railroad - Is not a good ending nor a good faction, there is no argument you can make to justify the Railroad's continued existence. Synth's simply can not exist, free willed, and peaceful or not. Intelligent or not. Synthetic people are not real people, they are advanced AI and will always be a threat to actual humanity. So any Human faction that protects them is a threat to humanity. Having said that, Then the Institute, the ones actually making the Synths are an even bigger threat to humanity. So they also must go. Regardless of how good they want to make it for people there will be no people if they replace them all with advanced AI. That leaves the Minutemen and Brotherhood of Steel. Minute men are good for the common wealth and the people but are also not tech savvy enough to identify Synths within their own settlements. That in and of itself is threat. The best outcome would be Brotherhood of Steel and Minute men working together to secure the common wealth.