If PaaS or some "run container as a service" setup can work for your use case, I'd probably go with that. It takes care of many things K8s does without all the baggage. Also you are not investing into anything that doesn't port easily to K8s in the future.

On the other hand, if you are thinking of using bare VMs, then better go with managed K8s. I think in 2025 it's a draw in terms of initial setup complexity, but managed K8s doesn't require constant babysitting in my experience, unlike VMs, and you are not sinking hours into a bespoke throwaway setup.