Which is why I suggest that RPG developers look into Dating Sims and AI Girlfriend apps.
Oh I hope fucking not lol. That would be horrible, games shouldn't become waifu/husbando simulators for lonely people.
It would only be horrible if they just copy/pasted from the bad Dating Sims and AI Girlfriend apps into the game.
"Looking into" simply means seeing how such things thrive based on creating a relationship with a character. These things create a feeling of a relationship being developed, which can help developers think about how to implement better writing and mechanics to their own relationship content (Less "Here have this gift/dialogue option to receive love" and more nuance and character development)
Of course, the key would be looking at GOOD Dating Sims. Ones that aren't just about obtaining waifus. But that have more depth and platonic paths.
Since, these are the best iteration of relationships in the video game market.
