I've been in software professionally for over 20 years and in that time I have only left 1 employer before 5+ years. I left after 8 months and it was because the company and org and team culture were a horrible, broken, dysfunctional mess, and the people who were capable of changing it didn't want to admit why they had the problems they had in the first place.
The work was essentially web scraping complex systems, which is not a case of "you don't need someone with my experience to do this" and more like I just didn't want to do it because it did not improve my current skills at all.
It is not like in the interview they told me: you will be doing web scraping for months on end. Or that I even thought to ask.
You've had a somewhat traditional career there by HN standards. Most of Silicon Valley was promo-hopping ever 1-2 years for the whole middle period of your career (somewhat curtailed now by the job market). It was really popular to FAANG -> startup for 6 months -> FAANG-1-level-up for a good chunk of the 2010s