AITA For Thinking My Sibling Needs To Help Me Clean?

My sibling, 26, and I, 24, still live in our parents two floor home. I inhabit the upstairs, the same floor as our parents, and they inhabit the downstairs. Before the pandemic our parents emptied our storage unit in hopes of moving everything to the back room. The issue is the entire downstairs floor is covered in layers of trash, so the storage unit boxes have been in our upstairs living room for years now. My sibling was tasked with cleaning the downstairs for years, but the mess only became worse. Last summer they got their first job, and I was permitted to enter their space to clean. Though this task is now considered mine, I have still asked for help from my sibling. But they tend to sulk or express guilt instead of helping, which only makes me feel bad for even asking. Still I am frustrated having to dig through their mess, and even more so because my work is easily undone. I know they have executive dysfunction and are unmedicated for a form of neurodivergence. I fear that they may not had the chance to develop certain skills because our parents had to deal with me being hospitalized for my mental illness throughout childhood. For these reasons our parents don't want to force him, nor do I, but I still am frustrated cleaning everything alone. Am I an asshole for asking them to lend a hand?