Bitcoin dominance is getting lower only because of the slower bitcoin network and higher transaction fees. Bitcoin was initially started as a low cost peer to peer transaction facilitator. However, with the confirmation time more than an hour and huge transaction fees of 998 sat/byte, makes it way more costlier than any other currency. That is evident why people are moving to other cryptos like ETH or Ripple or BCH.

I have also tried to make a transfer of around $370 USD few days back and the blockchain wallet was asking for $60 fees for the transaction. I aborted the action and now waiting for the network to come back to normal. Till the time, network doesn't come back to shape, it is hard for bitcoin to gain ground again.