Josiah turned to the LORD with all his heart (23:25). Why didn't the LORD turn from his wrath?

The chapter gives the reason in its own words, and the name in it is Manasseh's, not Josiah's: "Notwithstanding, the LORD didn’t turn from the fierceness of his great wrath, with which his anger burned against Judah, because of all the provocation with which Manasseh had provoked him" (23:26). In Manasseh's days "The LORD spoke by his servants the prophets" (21:10): "Behold, I will bring such evil on Jerusalem and Judah that whoever hears of it, both his ears will tingle" (21:12). When raiding bands come against Judah in the next chapter, the book says it again: "Surely at the commandment of the LORD this came on Judah, to remove them out of his sight for the sins of Manasseh, according to all that he did" (24:3), "and also for the innocent blood that he shed; for he filled Jerusalem with innocent blood, and the LORD would not pardon" (24:4). Huldah's word in the chapter before names the people too: "Because they have forsaken me and have burned incense to other gods" (22:17) (2 Kings 22's honest question on why the evil still comes takes that up). So the book says two things of Josiah's days side by side: there was no king like him (23:25), and the LORD didn't turn (23:26). It doesn't say Josiah's turning was in vain, and these notes add no reason beyond the one the book gives.