Does BCH use adjustable block size or a fixed block size of 32 MB?

I saw on the TXStreet website how the BCH blocks are mostly empty for now. So, just out of curiosity I wanted to ask you all, is this size for every block or there is a minimum size that grows upto 32 MB, coz I think an adjustable size would be a more storage efficient way of storing the blockchain. Correct me if I’m wrong.