Its my impression that bitswap was chosen/made, to have an easier time making "trading strategies" with other peers. BitTorrent would for that purpose be harde

Its my impression that bitswap was chosen/made, to have an easier time making "trading strategies" with other peers. BitTorrent would for that purpose be harder to modify, and claim backwards-compatibility, so I think they went all-in, and bitswap - with pluggable "trading strategies", ie how to decide which peer to share with and how much - how to avoid free-leach and so on. There was a mention of combining ipfs with filecoin - bitswap would make that integration easier.