A somewhat similar trend has been followed by the crypto market when looking at Bitcoin and altcoin pumps. When bitcoin is pumping, altcoins prices will decrease. Moreover, when Bitcoin is dumped, the altcoins prices will go further down. And when the price of Bitcoin consolidated after all this, then there is an altcoin season. Now, the majority of altcoins will test a new all-time high.
this much is true and I also seen the same similar pattern in which if bitcoin prices in general going up, it just doesn't mean altcoin will also go up, usually the dominance of altcoins are plummeted and got eaten by bitcoin first until the bitcoin price is going up so high and consolidate as you said and then thats the time for altcoin season.
meaning that if we are entering a new bullish era doesn't necessarily means that every coin out there would be going up at first it will be bitcoin with its massive rally and potentially reaching all time high and then the turns change. that is the time for altcoin to take advantage of the greed of the market and the bullish.
Yes, that's because sometimes the effect is delayed or the increase in Bitcoin is too small to influence the others. I think the demand of alts are still the same, it's just that sometimes there are new people who entered and they go on Bitcoin first. When BTC is rising, it gives an illusion that altcoins are falling but it wasn't actually.
If BTC price reaches to a higher point, people will be intimidated to buy and they may switch out to altcoin for a while. This is the time that altcoins can catch up and a bull run is officially started. Sometimes people will sell their BTC first, to have a capital. This allows us to see an altcoin season only while BTC price is already dumping.