Yes but every artist writes about break ups and Avril isn't going to be any different, however, Avril is one of those artists that doesn't always focus on love songs. Let Go was about finding your own identity and being true to yourself and so you wouldn't expect Avril to write songs about love in that album because she wouldn't have had that much experience, and yes there was quite a variety of topics. So as she's gotten older she writes more romantic songs because she can relate to those feelings.
Yes in UMS songs like DTM, MHE, TMA and Together are similar but that doens't dominate the album imo. I think songs like Slipped Away and How Does It Feel are about understanding life and overcoming difficult times (Slipped Away) and ultimatley finding our own place in the world. Then there are songs like Who Knows and Freak Out that are about living life to the fullest and not taking anything for granted. So I don't think that the angsty break up songs summed up the album
As for TBDT Avril was pretty "loved up" at that point so I would expect a lot of romance stuff in that album and songs like EBBY and TBDT are all made up stories anyway. I still think that album has variety though with songs like OOTG, Innocence and Runaway but is mainly focused on romance
I think in GL there was the most variety in the sense that she wasn't just blaming the guy for the relationship ending like her previous albums, instead she accepted that these things do happen and it's no one's fault. Also, I think I Love You is quite a unique song and isn't similar to anything she'd written before. Darlin and Everybody hurts are quite multi layered songs I feel, especially Darlin
I think Avril's always going to write about love but she can write songs that are open to interpretaion eg WYWH, IWY, Goodbye (to an extent) and Innocence. But I think it's naive to expect Avril not write love songs, it's where artists get the inspiration for most of their songs. And like I said, all of Avril's contemparies are doing it so it's not like she's the only one to only focus on love too much (which I don't think she does)
Also, she broke up with Brody this year so I'd expect a few songs about him but hopefully she's past the boy bashing stage now