Very difficult to change because, in the "Pax Neoliberalia" world we live in, profits are Sacrosanct - and the higher the capital concentration, the holier so.
But some straightforward fixes:
1. Flood the market with affordable state housing, Austria-style - with the bonus of building new, boosting the national economy.
2. Create very progressive (rapidly rising) taxes based on property value - making untenable the current practice of parking money and profit by simply buying & holding empty flats and the like.
3. Raise salaries - currently portuguese salaries, and their weight on GDP, rank the lowest in the EU.
(and no, it won't create an inflation spiral:
the current inflation spike is, first and foremost, the result of a supply shock, price-gouging and speculative/cartel practices - corporate profits being at a record high is proof of that)
Unfortunately, incentives are heavily stacked on leaving things as they are, as the ruling class is mostly made up of the landlord class, and, is not sensitive to (sometimes even not aware of) the struggles of assetless commoners that only earn income from their (low) salaried labor. Or, even worse, stands to lose their current large gains on capital/assets if this is fixed - and most portuguese media outlets trumpet their - private - master's voice and interests.
Additionally, just leaving things as they are, also scores brownie points with the EU by making the Government (even if "center-left") appear "frugal". And PM Costa has personal ambitions for future EU high office.
(...who will be the next head of the European Commission or the European Council?)