In my opinion, the issue was that they used this feature as an excuse to have other breaking features that weren't really needed. I think besides the string upg

In my opinion, the issue was that they used this feature as an excuse to have other breaking features that weren't really needed. I think besides the string upgrade, every other breaking feature should have worked with 2 to 3. Then they could have had a clear upgrade guide that is to run 2 to 3, then clear explanations on how to fix all the remaining string issues. Instead, I have no clue what 2 to 3 fixes and what it doesn't, leading to "2 to 3 will probably work, but if it doesn't, then you'll just have to figure it out yourself." That's unacceptable, and as a result caused many libraries to take a long time to upgrade. Personally, I had to spend 10 YEARS to wait to upgrade to Python 3 due to the wxPython library that all of my projects used that took that long to upgrade to Python 3.