Bitcoin was born from an international money crysis, where speculation, greed, mindless printing of money and over leveraged debt lead to a catastrophe that had the most effect on the most vulnerable, the poor. Bitcoin was created to fix money and to prevent this from happening ever again.
Satoshi had the vision to create a peer to peer electronic cash system, with no single authority controlling it, every peer can run a node and verify the ledger themselfs, everyone can use the chain without censorship, everyone can move money around the world without hassle and everyone could make payments with Bitcoin in an instant with minimal effort.
After a couple years and with more transactions being made, there was a need to increase the block size, this would permit more transactions to be included in one block, keeping the network fees lower. This was where Bitcoin left the P2P electronic cash behind, after it was refused by a majority of miners Bitcoin forked and we saw Bitcoin Cash being born which allowed bigger block sizes while Bitcoin stayed the same.
Bitcoin transactions started to be more expensive and Bitcoin shifted itself to a storage of value, much like gold, rather than staying in its P2P nature. This is where Bitcoin cash thrives, BCH continues the legacy of P2P transactions which was left behind by Bitcoin.
Peer to peer transactions are one of the most important thing about cryptocurrencies, it allows to circulate money in a decentralized manner without any restriction imposed. Also it's censorship resistant which means that no single entity can freeze a transaction or not allow it.
Bitcoin cash supporters chose to increase the block size to preserve what Bitcoin was in the very beggining a very effective peer to peer electronic cash.
Both structures are important, a decentralized way of storing value and an effective and decentralized way to move cash around the world, that's why BCH still thrives and still is widely used.
Bitcoin Cash is one of the closest things to what Satoshi Nakamoto envisioned.
