I don't see how this can be sustainable if everything goes up, not matter if it have any real value or not.
That depends on the bitcoin and i should remind you that when bitcoin can sustain even longer and altcoins will be following it but again only altcoins that have very good fundamentals can sustain from the dump.
The bullish trend is also happening with some altcoins but it was going down again. The pump can sustain even longer when altcoin has active development progress.
That being said altcoin will determine its future. The real value will come from the result of development progress.
I think the dump will not happen anytime soon but when it happens even the good altcoins do not survive it. Ethereum is the second biggest coin and has been very a very long time and it was 88 dollars at the bottom, before the bull run happened last year it was around 130 dollars, so I can easily say that over 90% to 95% fall is not something that second biggest coin should have endured.
I understand that people may not be increasingly happy with what they have, but that is going to be something that we will have to live with no matter what if the dump comes. ETH will be very low, BNB will be very low ADA will be very low Dot will be very low, all of them will be very low without a doubt. I understand that people have hopes that their good coins will stand and not drop as much as the other ones, but that's not true, all coins will drop if a huge crash comes.