Why are salaries so low in Spain?

I genuinely can't wrap my head around it. Spain supposedly has a gdp of $1.5T (32k per capita more or less). This makes it objectively one of the wealthiest countries in the world. Yet, the quality of life here is so bad for most people because salaries are so ridiculously low. Why? I genuinely want to hear your opinion.

IMO, taxes (total) are way too high, there is a heavy burden placed on business owners which makes employment expensive and leads them to offer low salaries. But im no expert and would love to hear from people who are or who just know.

Also, what is the solution? How do you increase salaries?