"" just shocked to see people hire others to be the mum""
I see that others have rightfully pulled you for that statement. If you've pumped enough, or aren't BF, then why is it Mum's job?
In this case, they are both working Parents. She's the one talking about it, because she's the blogger etc.
All of the research shows (and it's proven), that Women suffer more from sleep deprivation. It carries on affecting us, in the future, if you can alleviate that, then you should.
That includes Dad taking over, when he can, which still isn't happening enough, in general.
I used to take my GD, from five weeks, sometimes two nights on the run, so my DD could have unbroken sleep. She pumped well. There wasn't an issue with her bonding with the baby. I helped out a lot because I see first time Mums, not enjoying their babies, in a way that they should.
My DD has since split with her Partner, which I see more of, thankfully, than happened 'in my generation'.
Some of the tiredness etc you've got to get on with, but a lot of women don't have the help that they could have, I don't see the issue with buying it in.