If you’re in a relationship, then I’m willing to bet that one of you is more of the “money person” and one is more of the “free-spirited person”.
I think it’s extremely important that both the more financially-minded person and the non-financially-minded person are involved in the household finances and day-to-day decision making rather than one having full responsibility. If both people are handling/spending money, then both people need to be in tune with the financial goals and decision making.
If the non-financially-minded person doesn’t participate, they’ll end up sabotaging the plan and they’ll be screwed if something happens to the person who is solely responsible for the finances.
The financially-minded person can be the leader of setting up the budget and making sure that everything is in place, but they need help from the other person to make sure that the strategies are seen through and the finances are successful. On the other hand, the free-spirited person can help to remind to live in the here and now and not be TOO focused on saving for the future.
A balance needs to be struck between saving for the future and living a life that you can enjoy today.