It's a matter of taste on high sleepers. Some people love them for fbd floor space, some people find even the child can't sit up from quite young and the bedding is very hard to change.
We have a mid sleeper. I would not buy again - child outgrew the "cave" space and drawers underneath quite young but refuses a different bed so we are stuck with it sitting there empty. My preference is a normal, or build in bed, maybe a few inches higher than usual, and some really good solid wooden drawers on castors underneath. Storage under a mid sleeper is often quite narrow and seems a bit wasted to me as there's usually a big gap behind the drawers. If you use floor standing drawers under a normal bed, they can go much deeper under the bed and they hold loads. Add a few drawer dividers if you like. And a normal height bed is nicer to read or play on than a high or mid sleeper, so my other child who had a normal bed ended up with more play space, I think, than the one who got the midsleeper "cave" kind of thing. The latter do work for loads of people and we spent a lot of money on ours because it felt necessary, but for us it wasn't our best decision.
You could look at an Ottoman style bed that lifts up, or 2x kallax 4x1s used as a bedframe. It's quite hardcore but you can line them up so you have 4 accessible (say) fabric boxes on the visible side of the bed and another secret 4 ones stored directly behind them, on the wall side of the bed, and accessed through the open side by pulling the first ones out of the way.
Also rehanging the door to open onto the landing would make a huge difference, and wall mount some shelves for books, trophies, Lego model display etc.