The price of any asset attracts the traders only if it showcases it's higher levels of volatility. Woefully, Bitcoin in the past few days appears to have consolidated with less fluctuation. And hence the short term traders might have extracted their profit and shifted their focus on other altcoins.
No doubt, Bitcoin is manifesting a strong signal of a major bull run in the coming days, but currently, the other altcoin rally and dipping Bitcoin dominance might indicate the Altcoin season of 2021 is approaching very soon.