I would say you have wrong expectations about "get information from Opentelemetry". Opentelemetry is "integration" layer between collection of observability data (logs, metrics, traces) and their data storages. You don't need to stuck with one vendor, but you can combine them. E.g. you will use Telegraf to collect metrics, but you will store those metrics in the Prometheus.
So the answer doesn't depend on Opentelemtry. It depends on your observability data storage(s) - those must be supported by your tools (Nagios, PRTG dashboards).