This depends a lot. In most of the cases delay is only about 1 second on modern PCs. A bit more when you cite and build the document twice.
You can use LaTeX in many different ways. There are built-in editors and web services such as Overleaf. In the end, they all use the same workflow or dependencies for building the document, but might add an additonal delay.
I too have ended up tweaking my environment a lot. I ended up testing almost every LaTeX workflow.
I finally ended up for just using vim and zathura. Optimised docker image with LuaLatex builds the document. Second favorite would be LaTeX plugin for Jetbrains products. Overleaf is only good for collaborating.
On my desktop pc which has 16 CPU cores, there is only very little latency when compiling. But for text editing, it is a bit rare that you need such PC…