And doing THAT just adds to my confusion, because here’s what Activity Monitor tells me on my laptop after just it sat undisturbed with the culinary website open for about 1.5 hours while I toiled away on my indoor bike for an hour:

Immediately adjacent, my spouse’s brand new machine, unburdened by “memories” of the tasks of just over a year of daily use, managed to corral the RAM requested by the analogous process to a remarkably stable 1.27 GB, although paradoxically Activity Monitor DID report its “Real Memory Size” to be actually LARGER than on my machine.

What I’m concluding from this is that it’s not macOS all by itself that is causing this misbehavior, but something that’s happened along the way that I’ll probably never ferret out, and it leads me to infer that before I update to Sequoia it might BE prudent to do a data-disk-only backup of my Mac in SuperDuper! and then an erase and restore Sequoia installation of the System volume. Does that make sense?

--?
Jim Robertson