Well, aside from the hectic pace of having to uncover everybody who's ever lived birth & death info, temple rituals, seminary school for high schoolers @ ungodly hours, large-family care, extra work to pay for all your children's missionary work, countless do's & don'ts, etc.
When you look up "worthiness" (a key Lds concept) in the 1977 "Topical Guide to the Scriptures of the Church of Jesus Christ of Latter-day Saints" published by church-owned Deseret Publishers, you find verses like Doctrine & Covenants 59:4: "And they shall also be crowned with blessings from above, yea, and with commandments not a few, and with revelations in their time--they that are faithful and diligent before me."
"Commandments not a few"? -- sounds like a long checklist to me.
In Lds "prophet" Spencer W. Kimball's book, "The Miracle of Forgiveness," he said if Mormons "repent" of a sin -- but then re-commit that same sin...guess what? Well, that person never really repented of that sin in the first place! Imagine all the LDS "young people" who have "repented" of the sin of lust. But then they lust again. (Well, the LDS "prophet" said that then they never really repented of it to begin with -- they're all back to ground zero).
It's like imagining a spiritual game of Shoots & Ladders where most of the contestants always wind up back @ the bottom. Why? 'Cause it's a "game" based entirely upon the ability of somebody to self-will and self-repent once & for all from every single sin out there. Sins of commission. Sins of omission. All thousands of the types of sins out there. Catalogued 1 by 1.
Now that's depressing!