So no, its not worth it and hasn't been worth it for some time (I was there nearly a decade ago)...
...financially.
However, what was worth it was the experience I gained. Being the 1st non-founder engineer means you own a whole stack or specialty and you have no one to lean on. You have to figure everything out. Doing so propelled my career immeasurably. Without that experience I'd still likely be a very mediocre engineer. As much as it wasn't a good financial decision it was a great decision in terms of upping my skills, becoming a harder worker, and building a network with VCs and the local engineering community.
I had already worked at the Big 4 prior to switching and I didn't thrive in that environment. The startup ecosystem provided me the opportunity to work hard, network, build skills, and give me the tools & learnings on how to start my own business.
Not everything is about money.