So a while back, I was playing around with mirroring my android phone screen on my PC, really for no good reason. But to do so, and really to do a lot of PC control tasks on an android, USB debugging mode needs to be turned on. So I did that. And then after playing around with it, forgot about it for months.
Then, last night I dropped my phone and lost the screen functions. The phone functions and digitizer are just fine, but the screen is black. Thanks to the cloud, I have backups of all photos, email, calendar, contacts and such. (Android has a better cloud approach than Apple on photos, mail, and calendar but an inferior approach on apps, messages, and general settings).
I wanted to get into the phone to wipe the memory. How if the screen is black? Aha! I could mirror the phone screen onto my PC. Which I did and I got everything accomplished. It would have been impossible to do this, though, if I had not previously set USB debugging mode on, as that requires a bunch of screen taps. I did have to hit one OK to get the mirroring started (after that the mouse worked on the computer to make selections) but I took a similar phone and mirrored it, found out where the confirmation message was popping up on the screen, and was able to hit the right spot on the broken phone when I needed to.
So here is my advice for android owners. Broken or blacked out screen is probably the #1 smart phone failure mode. Go into your phone right now and turn on usb debugging mode while you still can. There is an odd process involving tapping a certain button 7 times to turn on developer mode, but it is explained here. The screen mirroring is a chrome app called vysor, which also requires some downloads of special drives but that is explained by the app.