To add to this view (of BTC dominance declining as a trend), coins like Ether and Gas can be seen as an investment in a commodity that has more value in the future.
Also, some people hold alts through bear markets. Period. Where before people would almost certainly dump most of their alt power into btc in the case of 'uncertainty', now only some of the space does that.

I am also unsure what to make of BTC dominance. @cryptovestor have you ever made a video solely on the advantages of using BTC dominance as a metric? Curious to learn more about it