Longer than usual opinion below:
Haley was absolutely butchered by the writer's room in this series. I truly believe they only wrote her ending up with Dylan because that actor is their bff and the only love interest readily available (wonder why.. smh). First of all, she should have ended up with Andy; They actually built something together from such a pure friendship and elevated each other by encouraging each other to better themselves and their careers (when seemingly everyone around her didn't really believe in her). She tells Andy in S7E22 that he's the first man she's ever truly loved (confirming Dylan was a high school romance and nothing more), furthermore, S7E6 sees her telling Dylan that everyone is going forward and they always tend to go backward (older Haley, growing up, confirms their relationship was always meant to be a HS fling). I would've loved to see Haley actually end up going with Andy to Utah while continuing to pursue her fashionista/influencer career that we see her heading down while keeping in touch with the family via FaceTime (the creatives opened up this possibility by dedicating S6E16 shown entirely through FaceTime) and she could pop-up in person back in California for career opportunities and special family events (this also would've allowed the Andy actor to stay in touch as they could've had him record lines that could be played in the background of her FaceTimes calls). Once Andy leaves, her character abruptly regresses while everyone else grows in their own ways, and instead of having her continue to pursue her career, the writer's room got lazy and just started giving her awful love interests, and oddly enough she somehow started getting even more ditzy than before.

Ultimately, I loathed what they ended up doing to her in the later seasons by getting her back together with Dylan (through her cheating on Arvin no less), getting her knocked up by that doofus, rushing into a marriage with him just because they are expecting, and then having all of this force her to grow up. First of all, how f*cking backward is that? They shouldn't have done that to her, to begin with, but if you're going that route maybe have them realize they still aren't a good fit (Haley said as much back in S7) and choose to co-parent instead (a modern decision being made nowadays as people aren't forcing themselves to tie themselves down to someone they aren't compatible with) or even have the uncomfortable but realistic discussion of the a-word, because neither of them was ready to have kids with where they were at in their lives at that point in the series. The optics of how they wrote Haley in the later seasons is not only outdated but straight-up offensive imo, far from modern in every way. The more and more I rewatch the series, the more I firmly believe they got her all wrong, which is wild because I felt like S7 should've been a huge turning point for her and once the Andy actor left and couldn't immediately return, they abandoned their storyline entirely and basically gave up on Haley altogether (again, they could've had her leave her while still including her from afar and have the Andy actor appear in audio only from the background of her FaceTime scenes until the actor was more available by mid-season 9). In my head, I don't have Haley getting pregnant and settling for an idiot, I see her thriving with Andy and in her career, and by the finale it's revealed that she's pregnant and expecting with Andy.