I'm curious why you think (4) seems unlikely -- is this a fact about your personality, or about the world (i.e. you think there will be no normal-ish jobs, and/or the world will not survive to see your retirement?)

Let me try to clarify. What I'm trying to say is that 1 & 2 seem likely enough that I won't need to worry about saving for retirement. And even if (!1 && !2), it seems very likely that I'll be both willing and able to continue earning money well past retirement age. Given these three things, it seems like pursuing 4 is unlikely to be worthwhile.