- are automatically assigned to an appropriate machine(node) based on explicit resource limits you define, enabling reliable performance
- horizontally scale (even automatically if you want!)
- can be deployed with a rolling update strategy to preserve uptime during deployments
- can rollback with swiftness and ease
- have liveness checks that restart unhealthy apps(pods) automatically and prevent bad deploys from being widely released
- abstracts away your infrastructure, allowing these exact same configs to power a cluster on-prem, in the cloud on bare metal or vms, with a hosted k8s service, or some combination of all of them
All of that functionality is unlocked with just a few lines of config or kubectl command, and there are tools that abstract this stuff to simplify it even more or automate more of it.
You definitely want some experienced people around to avoid some of the footguns and shortcuts but over the last several years I think k8s has easily proven itself as a substantial net-positive for many shops.