Google's John Mueller said in a Reddit thread that while the index status report in the old Google Search Console and index coverage report in the new Google Search Console are the same, they are "complied slightly differently."
The reason is that the new report tries to give you actionable steps you can take to make changes, while the other one was less actionable. John said "the new one focuses on patterns that we can tell you about, the old one is basically just a total list."
If you had to pick one to use only, John said "I'd use the new one, it's not only cooler, but also more useful."
Here is the old one:
Here is the new one:
Forum discussion at Reddit.