Although I didnt touch on BTC market dominance exactly, just this morning I wrote about BTC's future looking bright because of lightning network adoption, particularly with Coinbase recent move to implement it 100% on their transactions. Add to that Bitfinex implementing Segwit, which also helps transaction speeds, and fees, and we begin to see an aswer to the long standing "scale" criticism lauched at BTC.
check out my post if you like: https://steemit.com/bitcoin/@infidel1258/bitcoin-is-scalable-coinbase-implements-lightning-bitfinex-segwit
2018 might just be another magnificent year for BTC.