"Show me your flowcharts and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowcharts; they’ll be obvious."
I've gotten the feeling that flowcharts used to be considered quite important by lots of coders, while today they are only used in particular subcultures. A flowchart is sort of an ungainly artifact. It repeats information that is in code, but is more difficult to produce and save than code is.
I've found them worth the effort pretty much only when trying to explain to stakeholders that they have given me conflicting requirements. When they can follow the logic path with their own eyes they are usually able to figure out what they actually want
Nowadays code is (relatively) easy to read. Back in the day of thousands of lines of assembler, perhaps on punched cards, less so. I think that's why flowcharts were more important in the past than they are now.
Anecdotally every flowchart loving dev I've worked with has been utterly useless. If someone's first step is to create a flowchart of the entire structure of the project then I immediately know they are going to be a disaster.
This has certainly worked for me on smaller scale, but when things get big, it seems to break down. In theory, you should be able to look at subsets, but I've rarely seen things well factored enough that this worked well in practice.