There are enough people in Europe, I don't know why everybody is so concerned. Most people are doing bullshit jobs too, so those people could be doing something more productive, if that is something you're worried about.
One of the problems that worries people is that people live longer and longer and if fewer children are born the average age of the population will increase. That means that there will be more and more old people that don't work and likely require extra care therefore reducing the amount of normal workers even more.
Will society survive? Yes, obviously but it could probably have so severe consequences for people, and the countries.
Several evaluations suggest that policies that provide financial
support to families or paid leave at the time of childbirth have
a positive, but rather limited, impact in fertility. Of all the
policies introduced over the years, provision of childcare
services appears to be the most effective in encouraging
families to have children and women to remain in the
workforce.
French family policies provide a diversified system of
supplementary resources in the form of money, time and
services needed to raise children. The State provides support
to diversified types of families with children at ages from early
to late childhood. Another key ingredient has been the high
stability of family policies, based on strong popular support.
This stability gives confidence to families that they will benefit
from continuous support from the birth of a child until entry
into the school system and beyond. Such confidence creates a
favourable environment for the decision to have children