The entire premise of the device is built around issues in a relationship.
The campaign itself.
I thought it was for FWBs at first too, but it's meant to just be like... avoiding actually discussing your sex drives with your SO.
There's a video at the bottom where the creator and his wife talk about it and he basically goes "I could have just talked to her, but I might have gotten rejected" and like. Yes. Dude. You probably need to talk about that stuff.
No, I understand that much, but the idea isn't that having sex fixes the relationship. What's being fixed is the difficulting in aligning sex drives, which likely to happen often in a closed monogamous relationship.
It would be great if everyone went to therapy to get past the damage that our puritanical roots cause to our sexuality and learned to self reflect in a capacity that allows for easy, fluid communication about this sort of thing, but society isn't conducive to that.
Relationships encompass a wide variety of compatibility factors, and sex drives aren't always going to line up even in the best of circumstances.
It makes sense that something like this would alleviate the pressure of performing for your partner or getting them into the mood.
After all, open communication isn't going to magically fix the fact that one person is in the mood and the other person isn't.