I can view things from my partner’s perspective.

Perspective-taking sounds generous and is mostly technical. It means being able to state their case well enough that they would recognise it, rather than the caricature you argue against at two in the morning.

Try it on something small and stupid, like the thermostat. Their position is probably not unreasonableness. It is that they are cold, and were cold as a child in a house nobody heated properly.

Most positions have that shape underneath. You don't have to agree with the conclusion to find the reason it exists.