[...] we started adding ever-more complex layers of logic to operate our services.

As an example, Kubernetes allows [...] this can get quite confusing [...].

[...] this can lead to tight, implicit coupling between your project and Kubernetes.

[...] it’s tempting to go down that path and build unnecessary abstractions that can later bite you.

[...] It takes a fair amount of time and energy to stay up-to-date with the best practices and latest tooling. [...] the learning curve is quite steep.

So in short "it is complex so this and that may happen if you don't learn it properly".

Ok, this reasoning applies a-priori to any tool.