And just to save time: no, there is no firm biological distinction between men and women, the existence of intersex people shows that quite clearly.
This is completely preposterous. Putting aside for a minute that intersex people and orgs have repeatedly asked not to be used as a prop by trans activists, the occurrence of intersex in humans is extremely small.
And no, including conditions such as polycystic ovaries and hypospadias does not count as intersex unless someone is attempting to 'widen the umbrella' for propaganda purposes.
Intersex people do have a sex and with recent developments in medicine it's been easier to diagnose what is their base sex is when it doesn't present as obvious just by physical exam. Some intersex conditions only affect either male or female people.
Without the baseline of two sexes, two types of gamete there wouldn't be such a thing as intersex.