If you think all developers are interchangeable you're the reason they're forming a union.
That’s why they’re mostly autoworkers or longshoremen and whatnot an not professionals, outside a few niches motivated by ideology.
It sucks both for you and the company if they have to replace you.
In contrast, if you work building SaaS apps on top of k8s, you can both transfer your skills easily, and the company can replace you easier.
It could go both ways, but in practice it usually turns out that if your skills are transferable you make more money.
This thing also popped up in the gaming industry, with Unreal becoming popular, and people using it making much more and jumping between projects, because their skills are transferable.