The RAM usage you are describing is likely not actual resident memory use. Check RPRVT via top on macOS for a more generally useful metric of actual impact per process.
I look at memory pressure. I am running close to the yellow line on a 24Gb machine. If I close the apps, it craters. If I put more workload on it (I have a couple of things that will eat 4-5gb of RAM) it'll start crawling.
