A massive generalisation
Find me literally any statistics to prove otherwise
I don't need to, absolutes like yours are never accurate.
Anecdotally? my partner died suddenly leaving me deep in grief and a 10 month old baby.
My Mum was an enormous help but all the women at the babies groups she was in? no chance, never even came round to visit "someone else" was helping!
I v. quickly learnt child raising in the UK is a woman's world, chat to a mum at nursery and (female) tongues would wag! or people would say things like "oh isn't it nice to see a dad with the baby, your wife is sooooo lucky" that used to cut!
Now my daughter is at Uni, beautiful, sporty and balanced, i feel very blessed to have had the opportunity to be in her life.
But you are wrong to make assumptions like you did, every one is different and has different support networks or not, there is not this well of human kindness out there specifically for men
The OP's kids should be a bit more thankful for what they've got, life is fragile and one day, they'll give the moon and the stars to be with their Mum, like i would to spend a day with my Mum who died recently.