Thats basically the way I do it.

pvesh get /cluster/resources --output-format json-pretty | jq --arg k "lxc/$container_id" -r 'map(select(.id == $k))[].name, map(select(.id == $k))[].mem, map(select(.id == $k))[].maxmem, map(select(.id == $k))[].cpu')

Example using pvesh in proxmox. The data is available, just have to use it. I also prefer barabone approach.