Lesson learned: Altcoins are correlated to BTCUSD. When BTC falls, altcoins fall harder. This is a fact of life so get used to it.
The rare exception is what we call an "altcoin spring" like we saw in late 2013 or early 2017. This really only happens in the later stages of a BTC bull market, when there is speculative mania and people are looking to buy riskier and riskier assets. During those times, people sell BTC to buy into altcoins.
We're nowhere near that point in the market cycle. If my Spidey sense is correct, then we're still at least several months (if not a year) from getting there. The crypto market needs BTC to confirm a strong new bull market to new ATHs before it can enter a new "risk-on" phase.