Happiness itself is also subjective and varies enormously from person to person.

Your notion of what you reap in terms of happiness could seem bizarre and worthless to another. Likewise their idea of happiness and the goals they have pursued to achieve that happiness could seem just as bizarre and worthless to you.

Perhaps the only meta-goal is growth itself. Or as per Nietzsche:

One must want more to become more. For this is the doctrine life itself preaches to all living things: the morality of development. To have and to want to have more, in a word, growth – that is life itself.

I think it's fairly subjective wouldn't you say?

Would any goal that you set for yourself, as long as it authentically represents you, be a goal worth striving for?

In terms of "good", you would have to define what you mean by "good." Are you seeking to ground the goal in a moral / ethical foundation? If so, what would that be?

So, abolishing all pain and suffering to move humanity into a period of pure happiness, or degrees of happiness perhaps, without any suffering.

I wonder, is suffering / pain a catalyst for us, as humans, to enable reflection, growth, development, perseverance and an 'overcoming' or 'transcendence' of ourselves? (becoming more than we currently are).

Does suffering push us to find something higher? Does it build character?

How could the absence of suffering in this case, affect us, given the above?

With regards to evil, how would we conceptualize what is 'good' from the absence of evil? Does evil not teach us to appreciate, value the 'good'?

Perhaps some 'evil' is required for us to understand and appreciate the 'good' and to strive for it still, in the presence of the 'evil'.