Would it be wrong to throw away this stuff?

My dad looks organized, his bedroom is fine and everything, but he has three rooms in the house that are just filled with random stuff he just doesn't want to get rid of for no good reason.

My mom has told him to organize that and he says he will but he never does. He doesn't has to work anymore so it is not a matter of lack of time or him being tired, he's active and does sport and things through the day, but he just don't care about those messy rooms.

Would it be wrong if I organized all that and threw away literal trash he's holding on to (example: a super old white board they bought for me when I was little, dried pens, some of the too many random boxes)? I have no problem doing so and I have asked him to let me do it but he tells me not to since he says he will do it. I have a feeling this is one of the situations that happen when people get old and just do random shit that doesn't make sense.

Would it be wrong to throw away this stuff?
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