This is a good question, and demands scrutiny, as the OP makes a valid point concerning worship.
To answer this question, we must 1st examine an important truth which will explain John's purpose in Revelations:(Matt. 16:28)
Verily I say unto you, There be some standing here, which shall not
taste of death, till they see the Son of man coming in his kingdom.
To put this passage in perspective (John 21:21-23)
Peter seeing him saith to Jesus, Lord, and what shall this man do?
22 Jesus saith unto him, If I will that he tarry till I come, what is
that to thee? follow thou me. 23 Then went this saying abroad among
the brethren, that that disciple should not die: yet Jesus said not
unto him, He shall not die; but, If I will that he tarry till I come,
what is that to thee?
John "saw" Jesus returning with His Kingdom in power; in order to do that he had to be taken "in the Spirit"(vss 1:10/4:2) in which the laws of space and time were suspended so that he could see and record all the things that were "shortly come to pass"(1:1) so in this regard he is in effect, a 'time traveler', except God is showing him the truth of what will happen versus names, dates, scenes which describe certain individuals, which we see on 'time-traveler' programs.
Worship is of ultimate importance, and in Heaven, everyone worships God, and the Lamb. John does too, as one of the 24 elders who bow before the throne (Rev. 4:10-11),
The four and twenty elders fall down before him that sat on the
throne, and worship him that liveth for ever and ever, and cast their
crowns before the throne, saying,
11 Thou art worthy, O Lord, to receive glory and honour and power: for
thou hast created all things, and for thy pleasure they are and were
created.
In Matt. 19:28, it says,
And Jesus said unto them, Verily I say unto you, That ye which have
followed me, in the regeneration when the Son of man shall sit in the
throne of his glory, ye also shall sit upon twelve thrones, judging
the twelve tribes of Israel.
John is one of the 12 Apostles, and therefore on one of the 12 thrones(out of 24) which shall judge Israel and judge the Kingdom of God for all eternity. Therefore, to say he didn't worship in Revelations is inaccurate; he does worship in his capacity as an elder. However, in Revelations his purpose is to record what is happening, therefore he is like a camera man in the room who notices and records all that is going on, yet is not part of it.
Finally, all in Heaven and Earth bow before God, when God is revealed;(Phil 2:10)
That at the name of Jesus every knee should bow, of things in heaven,
and things in earth, and things under the earth;
Satan himself shall bow the knee to Jesus and declare Him as Lord; it will do him no good, as it will do those who worshipped Satan or the Beast in this life no good. But they will all acknowledge Jesus as Lord when all the facades are stripped away and we see things as they really are. So the issue of worship is of primary importance in the book of Revelations.