I think that existence is the good because, or rather when, (an) existence is actually good, and of course when (an) existence is not actually good then existence is not (cannot be) ‘the good’.
Thus to my view here there are values deeper than merely existing. Therefore existing is a value only when other values are sustained by that existing. Existing as a means to the ends of other values. These other values are precisely what I call the good.
Existence is good in so far as and iff it is actually good, in so far as and iff it actually sustains good values.
Health is similar, and appears intrinsically valuable for the same reason that existing appears intrinsically valuable, but is not, in fact, intrinsically valuable as it appears to be, and by the application of same rationale as above. But just as “existence” can be defined to mean “good existence” (thereby turning the question as to rather or not existence is the good into a mere truism, or tautology; begging the question) so too can health be defined to mean good health, healthy in so far as values beyond health as such are sustained. After all we can always ask, “Healthy to what end? For what purpose?” We can also ask, “Healthy in what sense, physical, mental, social, emotional, financial, intellectual?”
This is why I do not accept that statements like ‘health is the good’ or ‘existence is the good’ can really get to the bottom. In so far as those statements are true they already smuggle in unstated propositions as to which forms of health/existence are preferable and why; but this is done largely without wishing to discuss those variations amongst the possible kinds and ends of healths/existences, which is something that I notice Nietzsche tends to equivocate on most of the time.
When he isn’t equivocating and is actually trying not to merely beg his own questions, he ends up devolving into the same truistic statements as he started with… existence (survival, or thriving, or power) is good as such, or health (strength, power) is good as such.
Why does he merely rephrase the original questions rather than seek true answers from them? We’re simply just supposed to “get it” what he means, what he really means with these vague uses of “strength, power, thrive, become” type concepts as he inserts into the truistic equations. But I’m not too big on innuendo and “wink wink”, I want philosophers who know and desire precision.