Another interesting reason why the 24 elders can't be the church.

[Rev 19:1-4 KJV] 1 And after these things I heard a great voice of much people in heaven, saying, Alleluia; Salvation, and glory, and honour, and power, unto the Lord our God: 2 For true and righteous [are] his judgments: for he hath judged the great whore, which did corrupt the earth with her fornication, and hath avenged the blood of his servants at her hand. 3 And again they said, Alleluia. And her smoke rose up for ever and ever. 4 And the four and twenty elders and the four beasts fell down and worshipped God that sat on the throne, saying, Amen; Alleluia.

Rev. 19.4 This is the last time in the Bible when the 24 elders and the four living creatures are mentioned. After the great multitude in heaven says “Hallelujah”, the 24 elders and the four living creatures respond with “Amen, Hallelujah”—indicating thereby that the latter group is different from the former group. The great multitude in heaven speak of salvation, glory, power, and so forth; thus showing plainly that the church is included. The 24 elders do not represent the church. Hereafter they will no longer be mentioned, since after this time they must have resigned from their lofty positions.

The 24 elders are the 24 archangels in Rev. 4 which is a picture of heaven viewing earth.