I’ve never accepted the ‘too speculative’ criticism of sci fi and fantasy, all fiction by definition is speculative. One of my favourite series over the past three decades has been Terry Pratchett’s discworld, not the typical swords and sorcery fantasy but a set of comically fantastic characters and situations.
Early discworld novels were critically derided because critics saw only the fantasy and overlooked Pratchett’s subtly subversive humour. And of a trilogy late in the series, Going Postal, Making Money and Raising Steam (which are best read in order,) the middle volume Making Money is not only easy reading and very funny, it is as good an analysis of the fractional reserve banking system as you will find.
But Song of Ice and Fire is not all dragons and depravity, there is a lot we can learn about modern, polarised societies in it.
And from the perspective of present political developments, lifelong readers lime myself will see that Frank Herbert’s Dune series was quite prescient.