Aw, the eternal debate on “size”
Shorter generally means a faster tempo, but you cover less. Longer means you can get into more detail, but can be a slower read too. Also, there’s the attention span of the reader to consider, and giving them natural “stopping points” to come back later.
I’ve tried short chapters before (2K) and that was faster to write that story. OTOH, I tend to go for 7-8k averages for the contemplative/serious writings. However, if a chapter hits 10kwords, that’s when I’m looking to split (even if it goes “part A” and “part B”).