At this point, becoming suspicious that Apple intentionally puts things into macOS to fill up your disk over time and make you want to upgrade.

This machine lost 800mb over the last two days, even though I didn't create anything or update any software.

I went looking for stuff that might have been generated. Here's one. A directory of…copies of the desktop background images (which already ship with the OS in another directory.)

macOS creates new copies at random times. Forever. What.

[edit: Sept 7th, was the] Last day to send a short comment, in support of nationwide Covid wastewater monitoring which is in danger of losing its funding

A simple comment even as short as “I support nationwide Covid wastewater monitoring” is helpful
Takes less than two or three minutes to click through.
https://www.regulations.gov/document/CDC-2023-0055-0001

Calculators! Cigarette lighters! Why has no-one ever combined the two? Oh, wait: THEY HAVE (https://shadycharacters.co.uk/2023/08/ql-10/). Rounding out my series on Calculators of the Day, I give you the Casio QL-10 Calculighter.

(CC BY-SA 2.0 image courtesy of Vicente Zorilla Palau.)