Your own first link discusses this:
> In the first five years after drug policy reform, use of illegal drugs rose slightly among the general population but fell again in the following five years.
I remember looking at the actual figures, and what happened was that use of heroin in Portugal went down significantly, and use of all other drugs went up significantly, giving slight rise in total drug use on net.
> Use among 15-24 year olds fell throughout the decade,
This implies that use among other groups than 15-24 year old had not fell throughout the decade.
> and among the general population was lower in 2012 than in 2001.
The reason they pick year 2012 is because it's convenient to their argument, and they give out the game later:
> However, consumption trends in Portugal have been keenly disputed and often misrepresented. While drug use during individual lifetimes among the general population appeared to increase in the decade following reform, use within the past 12 months fell between 2001 and 2012. Both the World Health Organization and the United Nations Office on Drugs and Crime consider use in the past 12 months (recent drug use) or within the past month (current drug use) as better indicators of trends among the general population.18
> Since 2012, past-year use appears to have risen, particularly among those over the age of 25.20 This is, however, based on relatively limited data from SICAD (the Portuguese drug dependence agency) and only one further dataset — in 2016.
The lesson here is that there has been a lot of very dishonest reporting about the results of drug decriminalization in Portugal. You are just another victim of it. Omission of critical facts, cherry-picking groups and dates, and flip-flopping between different ways to measure as needed, are all very common techniques in crafting narratives, misleading people into believing falsehoods, without actually stating them outright, so that they can't easily be caught with blatant lying -- the blatant falsehoods then are repeated by people who were tricked into believing false narratives, which facilitates spreading it, while allowing the authors to wash their hands.
Of course, you don't need to trust some random guy on the internet who's too lazy to dig up relevant statistics, you can keep believing the non-profit industrial complex. You might spend some time looking up these figures yourself, but why bother, after all these non-profits would never lie to you, would they?