On smaller boats, one of the advantages to deck or cabintop stepped masts is that the mast and chainplates can be designed so the mast can be lowered and raised without a crane. My boat utilizes a tabernacle and is rigged in this manor. The chainplates are extended off the deck to match the height of the swivel bolt in the tabernacle.
I would imagine this advantage disappears as the boat length increases much over 30' as that dang mast is heavy!!
Rick in Florida