There is little here on how the 11 wears. The one owner with a long Kindle history reports a 2011 Keyboard model whose battery died after seven years and a Paperwhite 10 still in use but disliked for software glitches; the 11 was bought partly to get away from those problems, and nothing in the account says they have returned.
That is the whole of the long-term picture: a dozen owners in total, none describing years with this specific model, and no accounts of hardware failure, battery decline, or repairs. We cannot tell you how it holds up yet, only that no one in this group has come back to complain that it broke.