Those managed offerings will break (given time, everything breaks) and you're suddenly left with a giant behemoth whose insides you probably don't know well.

I've been there, when one node lost communication with another but not the rest of the cluster - and I've spent some time working with Linux network stack (I mean the actual kernel parts), so I had some clues - but nonetheless I've ended up just scrapping the node with all the workloads and starting a new one. Because I haven't found anything obvious and that was easier than continue debugging. But it wasn't exactly great or fun and painless solution either (I don't exactly remember what sort of trouble I had with draining node but there was something enough to make me swear at the monitor).

So I'm not exactly against K8s but I totally advise to realize its internal complexity (no matter if it comes preconfigured by a cloud provider - it is still there) and ask if one's okay to eventually encounter it.