RRD (zabbix/munin/...) is still better at long-term data storage - if you want to see multi-year trends then Prometheus will take ~TBs of space at its default 1

RRD (zabbix/munin/...) is still better at long-term data storage - if you want to see multi-year trends then Prometheus will take ~TBs of space at its default 15s resolution with no unified downsampling system.