Lore discrepancy the tree and lords

I need some help from anyone who has a better grasp of this than me. So everyone knows in the game that you can’t enter the tree because of the thorns blocking it. This makes sense there’s still shard bearers out there with equal claims to the throne too. What doesn’t make sense is the player being forced to burn the tree to gain entry. It’s stated that Godfrey became the first tarnished after being betrayed by Marika/radagon (they’re one in the same). It would make much more sense if the player could gain entry via defeating all shard bearers and gaining the rune of death Godfrey lost upon his assassination. I guess this is justified by the greater will abandoning the lands between and not wanting anybody to ascend the throne. The only way this isn’t justified in game as an option is because one of marikas children is all cocooned in the blood temple, and ranni cast hers aside. But still I’d like to know if anyone could clarify this for me because in a logical sense it makes no sense to have to burn the tree, at least in dark souls it was justified by Gwynn being a shadow of his former power and the flame dying.