Large and sometimes pointy elf ears where a thing before he was born, but I don’t know where pointy thing really took off. I suspect it was mostly a way to draw larger ears without it being as comical.

1870: https://freevintageillustrations.com/enter-an-elf-in-search-...

He did say in a letter that Hobbits had pointy ears seemingly a nod to existing tradition, while elves had leaf shaped ears whatever that meant.