Here in Spain I’ve seen people with +20y of experience contracting for <25€/h.

Salaries for senior devs range from 30k to 50k, with very little exceptions.

Yikes.

How much does a beachside bartender make?

And why would anyone so much as look at a C++ compiler error message even once for those wages?

Minimum wage is ~12k€/y, so bartenders get basically that. In Spain for people >25yo unemployment is around 40%, which obviously means you get a lot of competition for stable jobs.

Spain in general is very anti-business, especially small/middle business. I had not started freelancing until late in my career because having a paying side job costs you ~$300/month in taxes, regardless of your income this month.