As a human, when I have many tabs open, I observe that everything gets really slow. All applications get slow, but especially the browser. So I put on my engin

As a human, when I have many tabs open, I observe that everything gets really slow. All applications get slow, but especially the browser. So I put on my engineering hat and pull up Activity Monitor and further observe (a) high memory pressure, (b) high memory consumption attributed to Chrome or Firefox, (c) high levels of swap usage, (d) high levels of disk I/O attributed to kerneltask or nothing, depending on macOS version, which is the swapper task. I close some tabs. I then observe that the problems go away. Swap isn't a silver bullet, not even at 3Gbytes/sec. It is slow. I haven't even touched on GPU memory pressure which swaps back to sysram, which puts further pressure on disk swap. It's slow.