To name one, Portugal's bureaucracy is legendary. The Portuguese are not called "Honorary East Europeans" for nothing.
The red tape creates a complex system of inefficiency and corruption. It's like a cauldron – you (the government) plug one obvious hole, only to find the pressure found another, "unexpectedly".
And yes, young people run away in droves from Portugal, leaving entire industries back home chronically understaffed. Construction & health being two prominent examples that need foreigners to keep the lights on. This shortage of labour drives commercial prices up higher still, contributing to the death spiral.
¹ Leaving aside that both numbers are high to begin with; 48% ridiculously so (for anyone above €82k/year). That's no way to treat your productive population. And that's just income; there's additional health and social taxes, some masquarading as "insurance" or "employer contribution". Would you blame the young for leaving?