But I thought Portugal did the same (decriminalise) and by all accounts they've had fantastic results?

As I understand it they had fantastic results for the health and life outcomes for addicts. Never heard anything about it bringing change to the actual drug market and criminal groups.

I'd be curious to hear about Portugal's experience since it's been 20+ years since mass decriminalization. Whatever novelty effect is long past, and we now have a generation that grew up with the liberal policies. My quick search found articles written right after saying everything was going great, and obvious propaganda say that Portugal was nothing but a heroin den with everyone strung out everywhere.

Netherlands there are legitmate places to buy weed. Portugal, dealers will hassle you on the street (probably with fake stuff)

Most things aren't decriminalized, just psychedelic truffles (which are legal) and cannabis. Official policy is to tolerate everything, unless someone is being a nuisance.

The Netherlands is an interesting case. Despite amphetamine, MDMA, etc. being illegal, The Hague has turned a blind eye to massive industrial production farms in the south. At one point, the Netherlands almost held a monopoly on the world's MDMA production. Rumors of conspiracy suggest it's intentional, but the end result is the same. Many of these drugs are de facto legal, if not de jure. Of course, this was the landscape some decades ago. It's been changing. Mexican cartels are starting to elbow in, and it's been causing "problems". Watching how the government reacts to the evolving ecosystem is going to be intriguing.