PH culture has its twists. Filipinos love group celebrations (i.e. parties, fiestas) and so there's usually a birthday celebration at home where people get invited to. However, as not everyone is able to prepare a feast by themselves, some opted to treat the others outside (i.e. eat out). Hence, the expectation that when you have a birthday, you get to treat others out. ("libre naman diyan~")
I think giving the birthday celebrants a treat instead is better. Usually in office settings, at least people give them a cake. :)
Yes! Coming from that standpoint, it is easy to understand where the "libre naman diyan" came from 😊