This is pretty different dont come across this everyday. But apparently, birth rates are plummeting in Greece mainly due to people not wanting kids yet.
I think the factors affecting this is:
Cost of living= its too expensive, when you have a child the costs double. But in the last 20 years, bills in the western hemisphere have sky rocketed along with inflation and home ownership has gone down so people will naturally not think its worth it. This will put alot of strain on parents let alone couples.
Long working hours and low pay=if you work long hours you dont your family which can be really depressing being stuck in a routine which literally blackmails you and your family with homeless if you dont work all day. Only to get to pay and not have enough to make ends meet. So its probably better to just wait.
Social Media=this show off culture of extravagant materials, jet set lifestyle and party party. Set a negative perception about how we should live just chasing fame and money. People see this and think this is more valuable.
There are various factors but this is just my two cents.