@aegir I think BMI caught on because for a long time it was the only measure most people could track at all. These days it's easy to get a scale that also gives you body fat percentage, which is much more useful metric to track. Even if it's not very accurate compared to “proper” ways of measuring fat percentage on most scales it's consistently wrong so it’s still useful for tracking progress.
Congrats on the milestone.
@pointlessone BMI came from a racist attempt to prove the superiority of white European men, it was never designed as a means for tracking health. That came from the health insurance industry (likely as a means of limiting payouts, especially to non-white people). Most fat monitoring scales are inconsistent day to day as well as inaccurate.