Despite being very early adopters, we've only had one issue and when we pointed the finger at them...the DO k8s team immediately diagnosed the issue, and it was our own fault. Woops.
Some time ago i compared them against the competition and they fared very well even against GKE:
https://atodorov.me/2020/06/14/comparing-kubernetes-managed-...
In AKS, the API server & its backing storage, as well as most of the core controllers are "managed", in that they run somewhere not in your cluster. But then, you hit the issues where they must consume resources, and someone at the end of the day must pay for those.
I'd almost rather they run in the cluster, since those are resources I can introspect & debug.
(In a normal "vanilla" cluster, not a cloud-based one, normally these would all run inside the cluster, unless you configured them differently. E.g., kubeadm builds them into the cluster.)
In a default setup vanilla Kubernetes, you have master nodes which host the master services ( etcd, kube-apiserver, etc. etc.), and worker nodes on the side.
With managed k8s, in most cases, the "control plane" ( what normally runs on the master nodes) is run by the cloud host, usually on shared instances ( Scaleway did a talk and it runs on dedicated Kubernetes clusters, in a namespace per client).
Indeed, then you're subject to limitations ( e.g. the kube-apiserver for you is limited to 1000 MB of RAM and if you need more because you do X, you're screwed), but that's always the case - if you run your own master nodes, they have limitations as well ( based on instance/server size), just usually higher. There's the added risk that another customer might sature an unlimited resources and impact your control plane.
In any case, I haven't hit any limitations with Scaleway's Kubernetes so far and haven't seen anyone talking about having hit one, while this isn't the first time i've heard about Digital Ocean. I don't know if it's due to size or because Scaleway have higher limits.
Now that info aside, they do support cluster autoscaler.
https://www.digitalocean.com/docs/kubernetes/how-to/autoscal...
Or maybe it's more appropriate to say that Cluster Autoscaler supports them? This tool (CA) does scaling in both directions and is highly configurable. At least, it is for other cloud vendors so I'd guess it's going to be so here too.