I've already climbed most of the learning curve so YMMV, but as a team of one and dozens of WordPress, MySQL, and bespoke app servers, kuberenetes makes ops manageable so I can spend time on things that really matter.
Deploying new web apps is trivial, declarative manifests are easy to reason about, TLS certs are issued and renewed automatically (cert-manager), backups are cheap and reliable (daily GCP snapshots), making changes to the cluster via declarative terraform is a breeze, etc etc. No way I could manage all the ops without leaning so heavily on the core foundation provided by k8s.
I think that's the first thing with k8s: it all starts with an app that requires several physical nodes.
Most of the value I get from k8s is the hands-off nature of it - I get slack notifications (prometheus+alertmanager) if anything is happening I need to address (e.g. workload down, node down, API not responding, etc). Otherwise I can safely ignore my cluster and know everything's good. Spinning up a new WP site takes 10m with backups, TLS, monitoring, etc built in.
Well _technically_, sure, we could have run a bunch of those products on a single machine, but there goes your durability and the memory overhead on some of them was quite Hugh, and properly fitting them onto a single machine would have required more optimisation and technical skills than the devs I was working with had or were inclined to do.
I don’t think it suits all teams and use cases, but for us it’s absolutely fantastic and without going down the rabbit-hole of cloud-provider specific tools and recreating half the issues it solves, I’m not super sure what we’d use.