Welcome to post-Empire!

Portugal is incredibly badly managed and corrupt for an European nation, and this is actually an improvement over the first 3/4 of the XX century when the country was ruled by a Fascist dictatorship and so stupidly poor that it even received Food Aid from other countries in Europe. The country had a marked improvement following the Revolution which overthrew Fascism and another when joining the EU, but it's been going backwards for at least a decade (roughly ever since the Euro came to be, which coincided with the neoliberalization of mainstream politics here as the short period of genuine idelogies for the common good in Politics ended and was replaced by "greed is good").

Look around at almost all the imperial nations of 100+ years ago (for example Portugal, Spain, Greece, Egypt, Italy) and they're all at best mediocre. Look at the direction of travel of the UK and the US and the same destination can been seen in the distance (and specifically the UK, it's pretty noticeable how they're burning the wealth and institutions built/pillaged during grander years whilt not in fact creating any grand anything anymore).

Imperial nations rot from the inside and I suspect that once the culture and way of exercising powers shifts to the kind of parasitical behaviours that is only possible when "living of the wealth created/stollen in past times", it's very hard for it to shift back to whatever mindset created an empire in the first place.