My mother's a secretary (they call them administrative assistants now to be correct). She could advance her career by becoming a clerk, which mostly does more of the same, only more. Instead she's happy where she's at
I used to work for Microsoft. I left for a startup (peerdb) & while my pay didn't go down, that meant leaving behind >50k USD in unvested stocks & my salary growth at Microsoft was pretty fast (hired as junior in 2019, was one promo away from principal when I left in 2023) which I don't expect a startup environment to match