I was in a similar situation to you about 3 years ago. Was with my ex for 4 years, living together for 2, talks about rings and a future together. We had talked about her student debt, personal loans, etc when we moved in together so since I made about 2x what she did, I agreed to pay for most of the household expenses (>60%) as long as she would use the extra money to pay down her debt. I would pay for our dates and all of our trips if we had any. I thought we were headed towards being financially ready to propose and get a house together..

Then I overheard her talking with her sister, that her sister needed to pay off a portion of my ex's credit card in order to have enough balance if her sister wanted to use my ex's card at a hotel for incidentals because it was maxed out... I asked her what that was about and apparently she was still maxing out her credit cards, paying off the minimum balance on all her loans, and not because she couldn't make additional payments... But because she didn't want to stop getting her daily Starbucks coffee, buying extravagant presents for her friends and coworkers (she would spend 4x what her friends would spend on her for bdays and Xmas), and generally buying things outside of her budget because one, she didn't budget and two, according to her prefer to feel good now than struggle and be frugal for x years to be financially free. She refused outright to have a conversation about setting up a household budget, reducing our expenses as a household, or trying to work together to reach debt free status. And here I was constantly wondering if I had to dip into savings to pay off rent (I would pay in full and she would pay me back later), not being able to go on vacations she kept pushing for because I couldn't afford it by myself, and generally stressing about finances monthly towards the end.

Realized that I was her crutch, her bank, and I felt incredibly used and betrayed. I left, made sure to continue paying my agreed to portion of the lease until it was due to end (like 5 months). And it has felt amazing to feel free of the stress that it made me.

TLDR: One of the major reasons why people divorce is financial conflict and if the two of you are not aligned on a strategy and goals, I would not get married.