I believe that if everyone were to be able to use the same services, platforms, apps, etc. with the choice for them to be decentralized or centralized and with no effect on usability, then decentralized would be chosen naturally. The problem is that the most used parts of internet services are centralized and have already gotten the masses to their platforms. The challenge is creating just-as-good platforms that are decentralized and the even greater challenge is attracting the masses to these services.
Until there is a major problem with centralized apps/platforms/services that shines creates a need for people to transition to decentralized services, it will be hard to overcome these challenges. A large-scale cyber attack is an example of the kind of event that could force everyone to make the transition.