Please Make Boss Weapons Guaranteed Drops

I made it to the first boss and it beat me a lot but i finally managed to take it down after a couple of tries today and it felt great to learn the fight and finally win. But my only reward for the fight was a couple poise vials a dagger and a claymore that weren’t better than ones i already had. Knowing that there is a unique boss and not getting it after multiple attempts at the boss feels terrible and really demotivating. Boss weapons should be guaranteed from defeating the boss. What if this happens to a boss later in the game and you had to put in 50 hours to get there? Just feels bad