Oh - forgot about Fizban's, though that was a birthday present for me.Fizbans, last year October, unless they market something right at me its not looking like I'm interested in buying another.
Has 5E even been around for 10+ years? Because if your question is about the last 5E hardback, the answer is "Never". If it's any D&D hardback, it's probably "Whenever the core rulebooks for 4E were released", which I assume is 10+ years ago.Some folks buy every book, others pick and choose, and there are some who have yet to pick one up. How long is it since your last purchase of an official 5E D&D hardcover?