8 month old not getting from laying to sitting

Baby turned 8 months today and I saw the CDC milestone checklist says he should be getting to the seated position by himself by 9 months. He can sit unassisted if we get him there. He pushes himself up with his feet and flops around because the boy thinks he can stand and walk. He does pull to stand. He doesn’t crawl but turns himself in circles on the floor on his belly and rolls to get places. I’m kinda laughing as I type this because he’s his own little character, but I’m also like comeee onnn man. He does try to sit up unassisted and does a crunch, gets about half way there and flops down.