> How hard would it be to revert to the previous working version?

In Qualcomm EDL firehose mode? Super simple if you have the QPST: the phone is waiting for an image to write to the flash. It's actually waiting for the image to immediately reboot once it's written.

But google doesn't release these images, so it's like having computer permanently bricked after the hard drive was corrupted because there's no install media available.

I think we (as people who are on HN and can understand the problem) have a responsibility in not letting such things happen, if only because they hurt the people who don't understand the problem, the simplicity of the solution, and may just have a phone as their only computing device.