Getting kinda tired of the "world-changing power but only does things with it unintentionally" schtick.
Like it made sense early on but why would you notice your obscene amount of mana drop drastically as you try to purify an entire forest and still think you're living a normal life and have next to no curiosity about the world or your abilities? It feels like he's just waiting around until things happen to him most of the time. He is chronically uncurious about the world around him and just goes, "Well, I was never into those kind of manga", like this isn't an actual world he has to live in and interact with.
How have you been here months and not done anything other than try to walk out so far? Why do you just let the world happen to you? I'd get it in a slice of life series, but this is actively showing me horrible, horrible things happening repeatedly that the main character is completely unaware of so I just get to... continue watching the bad things until he accidentally solves the problem! It'd work as a comedy if I didn't literally watch people get assaulted repeatedly!
I kind of wish this story just didn't have the isekai component, and the MC was just the reincarnation of the King of the Forest or something. Nothing would really change plot-wise, and the MC's behaviors would be better explained as the ignorance of a child—a powerful demigod child, but a child nonetheless.
And just to add to your rant, I was really put off by the MC just not bothering to try magical communication with anyone, especially after all this time. Sure, at first he'd see them all as regular animals so he couldn't imagine communicating with them (and his imagination seems to be the most important part of his magic), but at some point he has to have noticed how smart they are, right? Or even if we give him not being able to imagine speaking to animals, he's wanted so badly to find people to speak to, but when he finds two kids, he doesn't even try then! What makes him think he'd be able to talk with the people of some random kingdom if these kids speak another language? May as well try magic translation or something; that has to be within the scope of his imagination, right? But nah, that's impossible: I'll just have to wait because, surely, civilized people speak Japanese.
