Contentment and complacency are ostensibly the same thing, though the primary reason I tend towards the latter term is because I think we ought to aspire to growth (in whatever sense you determine for yourself). That's just my opinion though. It's also worth noting that I have no way of knowing what others are aspiring to, aside from what happens in their life over the years (which can be a poor proxy, given the role of luck).
As someone who has a growth mindset I can assure you that in corporations like Microsoft or Intel (I worked at the latter), one's own personal growth is not only fostered, but highly encouraged.
Corporate life ain't for everyone and I get that. As a 56 year-old being squeezed out of the marketplace due to ageism, some of us aren't just after the highest pay or the most prestige at our jobs.
I don't see it that way, complacency can be just contentment from one's own perspective — it may take a third party to call it complacency (sometimes wrongly so, such as that parable[0]).
[0] https://thestorytellers.com/the-businessman-and-the-fisherma...
(Though that parable fails to account for unforeseen financial emergencies and such...)