not every employee (most?) is interested in gym, so why provide gym? you can make survey or research to estimate what size of childcare you will need
> On top of that, some would prefer an outside child care service, specially if the position has a lot of traveling involved (can your partner or caregiver bring the kid to campus when you are not there?) Even if you decide to do it. ¿How many people should you hire? ¿What happens when the employee is fired or quits? (it's hard to find a daycare center in short time), add insurance, etc...
just put in contract childcare ends same time as contract, simple as that, it's just bullshit excuse not provide option hiding it behind caring about well-being of employee