Speed and convenience is much more important than trust and safety.
Our society is set up in such a way that it doesn't give us much time to think critically for our own benefit. Decentralization comes with more responsibilties and people are constantly truing to reduce that. It is better to trust a 3rd party with your business affairs or daily transactions until even gets comfortable and no one starts monitoring them until they start acting maliciously to the point it is apparent. Ohh well, what a world to live in....
The most basic facet of human nature is to follow. To be sheep. This is why centralization will remain attractive unless something fundamental changes from our very own human nature.
We are still evolving