GPGPU usage is probally going to see some real usage. There was an interesting talk at the xorg conf even about turn the video hardware into virtual services running on GPGPU focused hardware.
Ive talked with some of the HPC programers too who are trying to find creative repurposes already lol
RKE2 is the next step up from k3s Same group mantains it (Rancher) but its built for bigger productuon uses (i.e. it deploys etcd instead of sqllite by default).