Oh no, it's useful, but it's as a herb, not something 'bushcrafty'
Look up rose noble, that was the common name for figwort in N. Ireland, some parts of Scotland and northern England.
We had a discussion about it not long since. I'll find a link.
Mine's setting seed, and the roots of the ones I weeded out are huge and starchy. The French call it Herbe de Siege ('scuse my French, school was a long time ago). We used to have an old Irishman as a neighbour and he talked about the RoseNoble. He said his parents pulled great bunches of it...
bushcraftuk.com
It's used really for skin inflammation type things. It's a general alternative remedy at it's best in situations of poor circulation. Don't use if the heart has any issues.
That said, my old neighbour whose parents looked on it as their 'use for everything' type remedy, and their large family all lived well into their nineties.
M