How do you use bygone?

Could you elaborate on how exactly one might utilize the term "bygone" in the context of cryptocurrency and finance? I'm curious as to whether it refers to past trends or practices that have now become obsolete, or if it signifies a particular strategy or tool within the industry that is no longer widely used. Is there a specific example you could provide to illustrate its application, and what implications does this have for those operating in the current crypto and finance landscape?