Bitcoin would have to drop 85% in value from where it is now to only have doubled in value over the past year. I'll take 100% yearly value growth any day of the week.
Your argument boils down to claiming that a pump and dump scheme is sound investment because those who enter early can still earn some cash when the bubble bursts.
Ponzi schemes are similarly profitable but for some reason they are frowned upon.
I agree with you that Bitcoin price is hugely speculative. There have been many bubbles. Most notably, $100->$1000->$200, in late 2013 through 2014, and $500->$10000->??? in 2016-2017. The future is unknowable, but arguably much of the overall ~10^6 increase since 2010 reflects real growth in demand. I mean, only some thousands were fully aware of Bitcoin in 2010-2011. Now billions are.
Even so, I don't believe that it's a Ponzi scheme. Maybe someone controlling Mt Gox accounts orchestrated the 2013-2014 bubble. Mt Gox had huge market share back then. But now, I doubt that any player dominates enough to run a Ponzi scheme.
