I think every rule is optional. if you are going to play an elf campaign then every human is not "core".
One of my players is playing a wood elf monk. with the elemental something archetype. the truth is that, fortunately, this group enjoys non-combat play, so I'm not sure if they are optimized or not,we have fights, tons of them, but I'm not sure.
since this edition doesn't make you choose your race in order to maximize your class you can pick any race. Still there are good choices.
Halflings have their luck. that's powerful.
human are a good choice as always for reasons.
Wood elf give dex, you have to boost Dex but not necessary the same way that previous editions.