I can only talk from my limited experience. The company I mentioned was my first workplace outside of university, and since then more than doubled my salary. So I don't think of it as a career killer, but instead a stable environment to get yourself skilled up in what it's _actually_ like in a dev role.
Completely anecdotally, but the most productive I've ever been in a company has been was a company in 2016-2019 who was on a monolith .ENT Framework with no kube/container setup at all.
Sure, it felt like absolute chaos some days, but I"ve never felt more productive and in a flow as then, mainly because we weren't chasing the latest and greatest thing but focusing on what's working for us and perfecting it.