Pokémon - Solgaleo Steel typing explained

Alchemical symbols….pokemon/human fusion rumors running rampant…why does this sound familiar?

I'm ok with it being steel type.
But it doesn't change that it makes no logical sense that the Sun is WEAK TO FIRE!!
Like, Fire/Steel would've been great! I know, Heatran exists, but come on now! PSYCHIC?
I mean sheesh, I know Deoxys and Jirachi and all sorts of other star-related Pokemon are psychic… but it really grinds my gears that somehow this quote makes sense now: