Boundaries for passivity

Use of boundaries in ADHD relationships is still a mystery to me.

How are boundaries helpful in a marriage when the intrusive behavior they're meant to protect from, is passivity?

I could state I don't accept doing more than my share of housework. If my partner doesn't do his part, I have to choose between living in filth or do it anyway. It's the same with everything else: either wait a lifetime, or push ahead and do something to improve life, and resent the surge in workload that choice produces. Because ambition
means more work, but you were already prepared to step in whenever your spouse failed to do their agreed part, and so your workload was ridiculous to begin with.

Of course, if there are no children involved, it's possible for a spouse to choose to spend more nights out or seek other company. But when you are tied firmly to the home by children's needs? Is it really possible to make boundaries that make you not notice the stinking garbage under the sink?

I think I haven't understood this. Still I know there are people who make boundaries and thrive by them.