The point here is that the Hebrew says, "Son of Man" so why not translate it "Son of Man"?I will list some verses from both the NIV and CSB.
Numbers 23:19a
CSB : God is not a man, that he might lie, or a son of man, that he might change his mind.
NIV : God is not human, that he should lie, not a human being, that he should change his mind.
The term 'son of man' here just means a person --not God.
Psalm 146:3
CSB : Do not trust in nobles, in a son of man, who cannot save.
NIV : Do not put your trust in princes, in human beings, who cannot save.
The CSB renders it as son of man. And it clearly means a human being.
Isaiah 51:12
CSB : Who are you that you should fear humans who die, or a son of man who is given up like grass.
NIV : Who are you that you fear mere mortals, human beings who are but grass.
Need I repeat that the term son of man is referencing people not Jesus?
The wording of the CSB is a bit awkward "given up like grass."
I like the NLT wording: So why are you afraid of mere humans, who wither like the grass and disappear?
Psalm 144:3
CSB : Lord, what is a human that you care for him, a son of man that you think of him?
It has a footnote saying :Or a mere mortal.
NIV : Lord, what are human beings that you care for them, mere mortals that you think of them?
That verse should remind you of Psalm 8:4. Yes, it is speaking of people --not Jesus. Psalm 8:4 and Psalm 144:3
speak of human beings --not Jesus. Don't get hung up on the term 'son of God' -- don't think it applies to Jesus every time.
The term does very often mean simply 'man,' but there is a clear and well-known reference to the Lord Jesus Christ in Daniel 7:13, to which the Lord Jesus refers in Mark 14:62 etc. The context usually decides whether there is a messianic reference to 'Son of man' but it is not for the NIV translators to decide on behalf of the reader whether or not he will be allowed to find Christ in the Bible.
There are plenty of other problems with the new NIV. I was not much of a fan of the old one, but the new one is unquestionably worse, and if people want a dynamic equivalence Bible, I think they will do better with the CSV. Better than either, of course, would be to rely on the NKJV, ESV or NASB, which are much more accurate.