Personally for me what I'll always say is that the mere fact that bitcoin has survived until now from 2009 coming alone is one fact that justifies its sustainability. Sure, pricewise, it's panting (and that's even for those who bought at the top at $20K) and has many critics. Other than that anyone who's been around for like 5 years ago knows Bitcoin is still big. So I'll say it has a higher survival rate, and the future is going to be more awesome👍