I use Netdata with the fping plugin, also supports Prometheus and uses few resources.
You could simplify your setup by getting rid of Telegraf (if you don’t use it for anything else), by setting up the blackbox_exporter1. It can track various pings, but also latencies for several types of requests (SMTP, SSH, HTTP, …). Since you’re using Prometheus it might be a better fit. However, the setup is not straightforward— you set it up on one machine, and then Prometheus queries for various latencies/responses.
Yes I’ve used blackbox_exporter in the past to alert for SSL and HTTP requests (status code == 200). Why I didn’t go ahead with blackbox this time is because it doesn’t give much useful data for ICMP