tl;dr: Firefox is the last major browser with an independent engine, and abandoning it over minor complaints (like its presence on X) risks leaving the web dominated by Chrome and its derivatives, with only Safari as a niche holdout. The author argues that critics—particularly on Hacker News and among bloggers switching to Chromium-based alternatives like Vivaldi—are being inconsistent and shortsighted, and that supporting Firefox is essential for preserving browser engine diversity.