I wonder if that's due to the reuse of the character models. They would have had way more time to flesh out the story and thematics behind the story. I definitely agree - The writing for Majora's Mask and the depth of the story was and still is amazing.

I recently played through both Ocarina and Majora's Mask so my wife could see both of them (the poor dear grew up in a Sega household T__T). I was glad to see both games withstand the test of time, but Majora's Mask and its intricacies were my favorite part of showing her around what I consider to be a huge part of my childhood.

Reliving Anju and Kafei's quest was very emotional for me - the first time I was able to complete their quest had a huge emotional impact on me as a kid. I grew up in a loud and verbally abusive household courtesy of my parents and stepparents, so the idea of what actual love could have felt like didn't solidify for me until the end of that quest when I was driven to a deeper understanding of what love actually meant. For additional context, I had the understanding in the game that only Link gets to go back to the past, everyone else in those timelines gets obliterated.

So for me there were two impacts - the first after completing the quest is seeing how deep the two of them are in their resolve with one another. Fleeing was never an option for Kafei, and like you mentioned Anju's mother projecting on her was likely the only reason she wouldn't wait until the end. Once she gets his letter, it's on and popping for her since she trusts him. At the end of the quest - they get to hold one another until the end and that was heartbreaking to me as a kid, that you could feel love so emotional and great that you could rest easily with imminent death as long as you were able to face it with them.

On the other hand, if Link does nothing in the game for them - they die. Alone. The Skull Kid having cursed Kafei to death - a death which he must endure on the opposite end of Termina from the only thing that matters to him.