When building Chrome for iOS from source, Safari Web Inspector can be used to debug a web page rendered in Chrome. However, this takes a non-trivial amount of effort which includes setting up a Chromium checkout, installing a current version of Xcode, and waiting for the build to complete. Additionally, a Mac with enough disk space to hold the code and tools is required. This barrier to debugging has led to bugs being filed for specific website failures on Chrome for iOS.
These bugs can be difficult to diagnose as they are generally based on a single failure case. Chrome developers most likely don’t know the website application well enough to fully understand what is causing the bug. Often, the reporter has even spent time to build a dedicated test page to more precisely understand the issue. The lack of debugging tools require developers to come up with alternative methods in order to debug their websites. Of course, nothing is wrong with filing bugs, and we certainly don’t want to discourage it, but we do want to improve the web developer experience.