what approach is better in your opinion?

Without question: using the PV and PVC. Half the reason will go here, and the other half below. By declaring those as managed resources, kubernetes will cheerfully take care of attaching the volumes to the Node it is scheduling the Pod upon, and detaching it from the Node when the Pod is unscheduled. That will matter in a huge way if a Node reboots, for example, because the attach-detach cycle will happen transparently, no Pager Duty involved. That will not be true if you are having to coordinate amongst your own instances who is alive and should have the volume attached at this moment.

it is important to notice that I want my K8s to Cloud agnostic so maybe forcing EBS configuration is less better that using a folder so the ec2 does not care what is the origin of the folder.

It still will be cloud agnostic, because what you have told kubernetes -- declaratively, I'll point out, using just text in a yaml file -- is that you wish for some persistent storage to be volume mounted into your container(s) before they are launched. Only drilling down into the nitty gritty will surface the fact that it's provided by an AWS EBS volume. I would almost guarantee you could move those descriptors over to GKE (or Azure's thing) with about 90% of the text exactly the same.