I think these sorts of reports forget to mention that Portland was one of the US's fastest growing cities for 5-10 years prior. It was the last "affordable" cities on the west coast and two big employers in the area Intel & Nike were growing like crazy... causing property to basically become unobtainable. Since the pandemic, both employers have solid remote work policies and so a lot of people have moved to more affordable areas.
I doubt crime is far less of an issue than simply available housing. It's still hard to build in the area and property is still very expensive. I know people that sold their homes extremely quickly in Portland and and others trying to buy into the area and just completely unable to purchase a property to move.
Ideally the trend of more people moving out than moving in continues until Portland housing stock can meet the demand.