While I agree that life is given without consent, I don't think that had to be a reason you can't enjoy it.
For me personally, I did feel pain in my life but I also felt and enjoyed a lot of happy moments, with my family, friends and alone!
While it's true that creating life can be seen as betting that your child can be in a lot of pain throughout its life If not taken care of enough is a bet I am ready to take!
For me, Life is an experience everyone should go through, I think of it like a big video game, a very long game:
A game that everyone is forced to start, if for a certain time they don't enjoy the game or hate it, they can leave and finish the game, if they enjoy it they can go through it and once they have done everything they were to do, they can leave and end the game. In both those scenario the end is the same, you turn off the screen and leave!
But its not because you were forced to play it that will you instantly hate or love it !
Well I think of life the same, there is going to be a lot of pain and suffering, if you are ready to continue in hope of joy and happiness then you are welcome to, if you really want to leave this world because you think that life is eternal suffering and non worth it, you also can!
Now that we set up my philosophy on life, I can start explaining why I don't believe in antinatalism...
I believe that after life is the same as what is before we are born, so life is just an experience that everyone didn't consent to but that will end the same
If someone has a child, the child has the free will to either continue on the path of life or enjoy it to its fullest, as in the end it will end the same, the experience of life is more important than the lack of one
And even if the child is in pain due to life and did not finding Joy in life he can wait a few years before exiting, but has exiting sooner or at the end is equal to the same result the consent of life transforms in a period of forced life that after a few years one can leave if not happy enough!
Of course I understand people that believes in antinalism and I don't think I don't condone to it as I think most philosophy is right even if you percieve it as wrong !
I hope that I was clear enough to make my point, English is not my first language and I am still learning !