To degrees, but Spain's fertility rate is appalling even by modern western standards. ~1.1 vs ~1.6 in the US. It's a huge difference and closer to the East Asia collapses than to the US.
One thing to look for in the EU is free movement of people. Young people can and do migrate to regions that pay them more. It would be interesting to look at Spanish youth migration to see if the younger workers (i.e. those more likely to have children) have moved elsewhere. That would create a further dent on the stats.
Isn't Spain one of the desired places for young people in Europe? I always saw people going to Spain, Germany or Switzerland for bigger salaries (e.g., people emigranting from Portugal)
Overall life quality is better in Spain, but not the salary at all.
Nuh-uh. Sadly tens of thousands (official figures around 70-80k) of young people emigrate from Spain each year.