I'll admit I went to the D&R tour mainly out of loyalty. I like seeing the new spectacle between tours and D&R certainly had highlights (CMT Awards version of CB, drums, etc.), but as a whole I'm not too excited to see her perform basically the same set of songs each tour (namely the LN/UI/CC/FOTF conglomerate and BHC encore). Those are generally her bigger, upbeat hits so I get why they're always on the setlist. But at this point I'd rather hear her sing Southbound and especially PC and VH given that it was the D&R tour and she said she recorded the album with touring in mind.
To me Play On is still one of her more fun tours. It was still relatively early on in her career where she didn't have as many "signature songs," which gave her more freedom to sing album tracks like What Can I Say, Songs Like This, covers from multiple different genres (Summer of 69, Take Me Home Country Roads, HGTA) along with the rotating genre each night, at least briefly. Carrie doesn't typically deviate from the normal melody or do runs except maybe briefly for award shows, but the Play On tour was when I felt she was most vocally experimental and acrobatic: the extra high notes at the end of Last Name, the vocal run at the end of Wasted that I love that she doesn't do anymore, incorporating a variety of songs into Songs Like This (White Liar, Single Ladies) and the runs at the very end.
Also, Some Hearts is nearly diamond. Rotate in Starts with Goodbye, The Night Before, Lessons Learned, etc. Like her or not, but Taylor Swift really knows how to get people wanting to see more than just one show each tour to the point that, combined with her stardom, tens of thousands of people tune into live streams and watch uploaded YouTube videos to see different surprise guests, hear secret songs each night, etc. It also gets attendees re-listening to literally her entire catalogue on streaming platforms leading up to the show to make sure they're prepared for whatever surprise song they get.