Another classic FP talk is Rich Hickey's Simple Made Easy. I think he does a great job of talking about the differences between things that are simple, and things that are merely easy.
Functional Programming
I thought this talk focused on history a little too long but really enjoyed it. I've toyed with the idea of making a language (probably never will) and it really made me reconsider what I consider important in a language. "Stop writing dead programs." The parts I remember sticking out were calling a lot of things cargo cult mentality that I had never viewed as that before. I don't necessarily agree with everything but it was a fresh and well organized perspective.
There are quite a few variations of this talk, but I really enjoy Conal Elliott's talks about compiling with categories here's he's 2020 Haskell.love conference talk. I always appreciated the way his work helps me structure my thoughts about evaluation of functional expressions.
Roc at Handmade Seattle 2021 detailed optimization done by its compiler to make programs go on par in speed with imperative languages' implementations.
I'm a big fan of Fun with Semirings ! It's about solving graph problems with linear algebra and certain algebraic structures in a very pagerank-like manner