You might decide to live with this but again, if you started thinking about it to the point where you consider breakup then it's likely a serious enough issue and it doesn't get better.

This shouldn't stop you from trying to the point where by all definitions the relationship is dead. There's no rule for this other than a rule of thumb. But that one pretty much suggests at that point you are just delaying the inevitable. Unless all you actually need to fix it is time.

It might not always be simple or easy but if you're in a bad and unfulfilling relationship then it's up to you to swallow hard and move on. Staying is lost opportunity.

A divorce has both higher emotional cost - especially if you have kids and are close to your in laws - and financial costs. If my job causes undo stress and hardship, I will leave at a moments notice. If my marriage is causing me stress and my spouse is willing to put in the effort to help us come to a better place, I’ll do what it takes to make things better. I’ll go to marriage counseling, but there is only so much you can do in an organization.