Telemetry is the lazy, unthinking approach developers typically take. They think the telemetry data tells you what users are doing and how. But it doesn't really. It does not tell you how easy, difficult or frustrating the user finds using an app. It does not tell you whether the user accomplished their goal or gave up in frustration.
If anyone still thinks running a usability study (to spot usability problems in an app) is too complicated, read this 20+ year old article from Jakob Nielsen (of NNGroup):
Why You Only Need to Test with 5 Users: (published in 2000)
https://www.nngroup.com/articles/why-you-only-need-to-test-w...