21 is her best album period but 25 is next with ease. I find 19 her worst album mostly because it feels like she didn't know what she wanted it to sound unlike 21 in which she felt more focused and more authentic than with her debut. So to certain extend she kinda declined in quality but that's because 21 is so good that it was easy to match its quality.
I think so. I got 25 as a Xmas gift and only listened once. It's crazy, because I played 19 and 21 to death. I agree she is missing the unique more alternative tracks that made those albums special
No. 19 is her worse album. 25 is arguably a better listen than 21 is so I would say she has been improving. I can see why some people like 21 more though