This is the kind of thing I expect has been done before.
On my work computer I typically run a ping in a terminal window that goes across my work VPN. That VPN is not reliable even though my home network is; periodically I will lose packets for seconds at a time, or the pings will start coming back in the hundreds or thousands of milliseconds. If my computer seems to freeze up, I’ll glance over that to see if I’m having VPN connectivity issues.
It would be nice to turn this into a menu bar item - green if it’s ok, yellow if pings are slow, red if pings are failing. I feel like this is probably doable in something like Swiftbar, but before I go re-inventing the wheel, I’m asking if this kind of thing already exists.