Why am I getting empty expression data from GEO?
I am sure the data is legit, you are just approaching it incorrectly. getGEO is an application for microarray data, not for digital count data such as (sc)RNA-seq, therefore what you aim to do is simply not possible by design. Unless you want to start from the raw reads why not taking the at the file named GSE116237_scRNAseq_expressionMatrix.txt.gz provided at the bottom of https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE116237?