It is culturally popular nowadays to say that gender is a spectrum, and that women and men are not substantially different. I have seen people actually claim that biological sex differences don't exist.
It's easy and popular in some contrarian subcultures to make fun of those views, and point out how inconsistent they are with reality, or how those views conflict with other culturally-popular views about how "men" are aggressors and an unequivocal danger to "women".
Insulting the stupidity of these beliefs is not a biblical response. The biblical response is not to make fun of falsehood, but to state the truth.
In God’s image he created him; male and female he created them.
Even if it doesn't seem obvious, humans come in two sexes. The Bible recognizes exactly two genders.
A woman shall not wear men’s clothing, neither shall a man put on women’s clothing; for whoever does these things is an abomination to Yahweh your God.
The Bible says that pretending to change your sex is an abominable sin.
People talking about trans rights are not suffering from a failure of intelligence, but the same sinful failure that is common to all of us without God's help.
Contradicting God's word on sex and gender is a sin.
If they confess their sin, Jesus is faithful and righteous to forgive their sins, same as he does for any of us.