> the issue is that the browser simply never suspends tabs I haven't used in days or weeks. Modern browsers are not good "desktop citizens", if you will. They hog memory to the point where opening anything new will create a pressure stall.

The "Auto Tab Discard" extension[1] for Firefox unloads tab contents, keeping only the title and favicon. Tabs can be put in an allowlist to prevent discarding. I don't know if Chrome or Safari have something similar.

[1] https://addons.mozilla.org/en-US/firefox/addon/auto-tab-disc...