That's a weird claim considering no one said that.
There are currently two long-term maintenance opioids on the market: Suboxone and methadone.
Compared to committing crime in order to afford a $200+/day heroin or fentanyl habit, regularly overdosing and/or living on the street, yeah, these drugs can be life saving and let people live normal lives.
They of course have their downsides, they're still opioids and you're still addicted if you take them, but they're legal, pure and given under controlled conditions, which seems to eliminate 99% of the life threatening/ruining effects of illicit opioid addiction. People can live functional lives on them, which given the alternative, is pretty nice. It also shows that drug use, under safe conditions, doesn't necessarily result in a long-term crisis.
That said, the only people who should consider long-term maintenance opioids are people who are going to die or end up in prison if they continue taking heroin/fentanyl/etc. The idea that "everyone should take this magical substance" is a joke that no one has ever claimed.
Plenty of people live normal lives while on Suboxone, where they might have been living on the streets and doing things no one wants to do in order to obtain illegal opioids. A lot, if not the majority, of those people used illegal drugs as coping mechanisms.
Criminalization, lack of supply, lack of purity of substances and lack of public health treatment are really what makes opioid addiction a life threatening/ruining problem. Things like Suboxone address all of those issues, and the successful lives of Suboxone patients say a lot.