Excellent point!
The small word
"and" (implication: "Also") which exists between Jesus' words
"of water AND of the Spirit" in His discourse with Nicodemus about the matter, albeit, as you've noted, is not always recognized by many, it is, nevertheless, of signicifant importance.
One without the other renders one's eternal salvation incomplete (as evidenced by the example regarding the people at Samaria -
Acts 8).