Please read Revelation again.
In Revelation 8 we have a lovely picture of incense and prayers rising before God,
Another angel with a golden censer came and stood at the altar; he was given a great quantity of incense to offer with the prayers of the saints on the golden altar that is before the throne. And the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel. (Revelation 8:3-4 NRSV)
This is such an amazing picture of prayer, and more than that, of our prayers coming before God.
There are two other verses which refer to incense and prayer, one more from the New Testament and one from the Old Testament:
When he had taken the scroll, the four living creatures and the twenty-four elders fell before the Lamb, each holding a harp and golden bowls full of incense, which are the prayers of the saints. (Revelation 5:8 NRSV)
Let my prayer be counted as incense before you (Psalms 141:2 NRSV)
Prayer is incense, is like incense and is offered with incense!
This says a great deal about how important prayer is to God.
“Another angel with a golden censer came and stood at the altar; he was given a great quantity of incense to offer with the prayers of the saints on the golden altar that is before the throne. And the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel.”
The angels are not praying. They are depicted delivering the prayers of the saints - later identified as those who die in the end times - to God. Nor are these identified as prayers of departed saints that were interceded to by a Christian on earth.