I see the current Bitcoin dominance as a temporary bear market phenomenon. I think many people have moved out of altcoins and back into Bitcoin, rather than returning to fiat. A flight to quality as it were in tough market conditions but this time staying in crypto.
I do think the next bull market may see Bitcoin dominance remain relatively high because the story will likely center around Bakkt, custodial services and institutional money specifically buying bitcoin as a hedge.
Ten years from now Bitcoin dominance should be far lower, reflecting a healthier crypto market. But Bitcoin’s had such a long head start, we’ll need a big story like an Amazon or FB introducing their own incentive coin to reanimate the market for application coins.