Just sounds like everyone has different definitions of "work", and that trips the entire saying up.
For you, the work is mediation and compromise.
For some dude further up in the comments, the work is referred to as "tedious", and probably means something else entirely.
For me, the work has been about doing shit I hate doing because I know it'll make wife happier. Compromising doesn't feel like work, because we're good at talking through scenarios until we figure out something everyone's happy with.
But for some people....they say "relationships are work", and what they mean by "work" is regularly suffering and accepting shitty treatment. And that's not normal or okay.