Yes, in Rev 8:5 you gloss over the fact that the elders are offering the prayers, or interceding, on behalf of the saints. Seems like a big thing to ignore. I also suspect you might be missing Hebrews 12:1 and a desire to see Scripture as the Ancient and undivided Church did and still does, in fact, only the modern man made communities reject the notion that the saints in heaven are very much alive in Christ and as such, as perfected in Christ, joyously aid in His good work. Why you and others reject the prayers of your brothers and sisters in heaven is truly a mystery!
RCC doctrine assumes two things, if your interpretation lines up with that:
a.) The saints mentioned in Rev 8:3 & 4 are in heaven. Scripture doesn’t tell us. They might be still alive in the flesh, on planet Earth.
b.) The saints in heaven have been petitioned by saints on Earth and are carrying those prayers. Scripture doesn’t tell us what content of the prayers.
Let me clarify one thing: I have not said that heavenly saints cannot intercede on our behalf. Rev 6:9 - 11 shows that they, in fact, do just that. I maintain that we who are on planet Earth are not to talk to those who have passed on, be they in heaven or in hell, except for to speak to our one and only High Priest Jesus.
Heb 12:1 shows heavenly saints either watching earthly saints (my interpretation) or witnessing in heaven - praising God - for His work in His people through the ages (a dispensationalist interpretation). This scripture does not show Earth-bound saints speaking to or praying to heavenly saints.