You are looking at a CoinJoin transaction, likely created by Wasabi. It’s a type of collaborative transaction that mixes the funds of many users together to break the links between individual inputs and outputs in order to improve each participant’s privacy.
As an example, consider the first two inputs (21.47483648 BTC each) and first two outputs (20 BTC each). You could reasonably assume that these each belong to the same pair of people, but there is no clue as to which of these two is the owner of which output. There is of course much more going on here, seeing as the transaction includes a few hundred inputs of multiple different denominactions, but this is the basic principle of CoinJoin.