> you don't know exactly how it's being used, which features actually need your attention, especially if you're spread thin.

Why not conduct a survey?

> vague bug reports instead of automated session recording and if you need to maintain that, you'll have gray hairs appearing by the age of 30.

If it's a customer, why not reach directly to him?

> with the system working okay at a load X, but falling over at X+1 and you having to spend late evenings trying to refactor it,

No one is talking about telemetry on your servers. We're talking about telemetry on client's computers.