I do disagree with you vehemently about Seattle’s light rail being inferior to Portland’s. That may have been true 10 years ago, but it for sure is not true today, especially after the East link opened earlier this year.
That said, Your parent is wildly off the mark (and honestly quite reactionary) in describing harassment from fentanyl addicts. Such harassment is extremely rare, and in the few cases where it does happen it is a failure of public health policy, not transit and accessibility policy.