Maybe they are, maybe not. Bitcoin bulls were shitting all over altcoins in 2016 too, making the same assumptions. Then the 2017 bubble happened.
I'm not willing to baghold anything down here, but I'm definitely keeping an eye on these charts. It might take a few more months for altcoins to bottom out but I'm seeing signs of accumulation.
Bubbles don't normally repeat with the same asset. You can check the 1999/2000 dotcom boom. Most of the stocks which crashed by 99% then didn't made a recovery. Only a very few of them such as Microsoft and Apple recovered to new ATH levels. The same is going to happen with the altcoins. 2017 was the peak year for them. The vast majority of the altcoins are never again going to achieve the peak levels that they attained in 2017. However, a select few may thrive and reach new peaks within the next 4-5 years.