What is the big deal with telemetry capabilities on your tx? 

I understand with the Taranis you get voice alerts for things. But without voice/vibration alerts for things like rssi, what the hell is the point if your goggles are on anyway and you visibly won't be looking at your tx?? 

Am I missing something?

I like telemetry for two reasons.

Firstly, an audible alert is possible depends on flight data conditions on the quad, it's useful when we are so focus into flying FPV and may not notice the OSD.

Secondly, the Taranis is a very convenient battery checker. If I'm not sure which packs are fully charged vs. which are used, I can just quickly plug them in to the copter and look at the Taranis. No need to get a separate battery checker out. Also, after the end of the flight, it's nice to see where the battery is resting, and I've already taken off my goggles to go pick the quad up, so I don't have OSD convenient.

I still want to have telemetry available even when I already have an OSD