The recent article on Quanta (by Natalie Wolchover) concerning $\aleph_1$ vs. $\aleph_2$ suggests that there is excitement within that community:
Juliette Kennedy: "It’s one of the most intellectually exciting, absolutely dramatic things that has ever happened in the history of mathematics."
Another instance is the Fargues/Scholze advances on "Geometrization of the local Langlands correspondence," which has the Langlands world excited:
Eva Viehmann: "It’s really changed everything. These last five or eight years, they have really changed the whole field."
This makes me wonder if there is something like a heat map for all of mathematics, which would show the areas with a lot of excitement. It seems difficult to capture this via arXiv postings, but that is an obvious starting point. Has anyone pursued this?