Rev 5:13
*And I heard every creature in heaven and on earth and under the earth and in the sea, and all therein, saying, “To him who sits upon the throne and to the Lamb be blessing and honor and glory and might for ever and ever!” *
Here is John, not yet a perfected saint in heaven, who is able to hear every creature in heaven and on earth and under the earth and in the sea. This is vastly, vastly greater than just hearing the prayers of a few hundred, or a few thousand, or even a few million people.
This same verse also helps explain those bowls of incense which are called the prayers of the saints. In Rev 5:12-13, as well as in other sections of Revelation, we see that the prayers of those on earth and in heaven which are directed to God are represented as spoken words. They are not represented as incense. So what are the prayers that are represented as incense, and which the saints offer up to God? They are, of course, the prayers to the saints, asking the saints for their intercession. Those are different in essence than prayers to God, and thus they are represented as essentially different in scripture. And the saints do exactly what the Church teaches they do with those prayers, which is that they bring those prayers before God.
Only by accepting prayer to saints can any sense be made of the two completely different types of prayer found in Revelation.