Where in Revelation is this condemned by God practice revealed as good?
5:8 “And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.” Hmmm. Context doesn’t tell what these prayers are, for whom, etc. Saints is a word that includes all who are born again in Christ and made righteous by Him - be they still on the Earth or physically dead and with Him in heaven.
8:3 & 4 “And another angel came and stood at the altar, having a golden censer; and there was given unto him much incense, that he should offer it with the prayers of all saints upon the golden altar which was before the throne.
And the smoke of the incense, which came with the prayers of the saints, ascended up before God out of the angel’s hand.” Hmmmm. Same discussion as above. No intercession described.
I don’t find anything describing God’s favor of living humans praying to people - on earth or in heaven, nor for humans speaking in any sense to those who have physically died - with the exception of the One who has risen from the dead.
Am I missing something?
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!