MacBook Air 2020 (i3) with 16GB. Use for general productivity work (Mail, Safari, MS Office, etc). Measured 11.5 GB free for applications under Catalina and Monterey doesn't seem any better. Normally runs fine but then Safari grabs all available memory and spills over into swap from time to time (lots of tabs open...). Restarting Safari helps (closing every window usually not enough) but also notice that WindowServer gets big and rebooting the only way to get the system running smoothly again. Probably would be fine with 8GB if it wasn't for Safari and runaway processes/applications. Bought 16GB because I knew it wouldn't be upgradable and wanted flexibility for the future.
MacBook Air 2020 (M1) with 16GB. For a college student. Runs well under Monterey. 8GB probably would have been fine for Google Docs, Minecraft, and Spotify but 16GB a little more future proof for lasting through college and maybe the year after.