Because he knew that at the end of this world someone is coming who will use that power completely in all the earth. That time is the time of perfection and everything, at that time, will attain its perfection and be complete. And all saints in this world, in this universe, await that miraculous age. We live now in a time of darkness. Saints now do not display their power.
Saints have the power to attract many to their association.
But they do not use it because they do not have permission. It is given them for specific purposes and is not to be used everywhere and on every occasion. And that is the reason why saints nowadays see only certain people, special ones. You cannot find diamonds everywhere, they are rare. I likewise, the followers of saints are very rare, like stars on dark nights.