I founded 2 of the companies above (1 acquihire, 1 sold big portion of my shares back to investors when I left).

Yes I agree founding is much better than being first engineer. Reason I kept joining as first engineer is because I found product market fit for my self (it's funny to say that haha). I was able to pitch myself as first engineer that builds first product and first teams. Someone super technical who likes to grow code and grow people is actually pretty rare in startup world so I was able to ask for high comp and choose to work on interesting projects.