Effective poems can be – and have been – written on practically any topic imaginable, and so in the strict sense there are no topics that are automatically unsuitable for poetic treatment. Some effective poems have even been written on nonsense. Lewis Carroll’s “Jaberowcky” comes to mind, which begins as follows:
’Twas brillig, and the slithy toves
Did gyre and gimble in the wabe:
All mimsy were the borogoves,
And the mome raths outgrabe.
Yet it seems possible to argue that the poems most likely to live and endure from one generation to the next are poems dealing with such “archetypal” themes as birth, love, family, sickness, joy, fear, happiness, nature, and death (to mention just a few). These are the kinds of experiences and emotions that people have encountered from time immemorial. They are experiences and emotions that are practically inevitable by the very nature of life and by the very nature of human beings. They are likely always to seem relevant and interesting and meaningful to humans as long as humans exist.
A famous (or infamous) poem by the American poet Aram Saroyan reads as follows:
That’s it: “lighght.” This poem won a $500 prize from the National Endowment for the Humanities back in the day (1965) when $500 was actually a decent amount of money. The award caused considerable controversy at the time, and it is hard to imagine that 500 years from now people will be reading this poem except as a strange curiosity. The poetry of Homer, Virgil, Dante, Pertrarch, Shakespeare, and many other “canonical” poets, however, is likely to endure, partly because that poetry engages with archetypal human issues and – even more important – is actually skillfully written. (Lots of bad poems have been written on love, death, etc.)
So, although it is old-fashioned to say so, the poetry that is most likely to continue living is the poetry that concerns the common, core issues of human life.