How is Tangled better than Frozen? Let's discuss!
TLDR: Acts 1 and 2 are surprisingly similar but the later half of Act 2 and Act 3 in Tangled is marketedly better written due to the set-up proposed in Act 1 and Act 2. Please discuss and keep things civil 
(please pardon any weird phrasing as I wrote this when suuuper tired for a FUN comparison between two similar movies)
Numero uno, all of the songs serve a purpose. The best 'twist' is the villain gets two songs, as both a hero and an actual villain in her reprise- in Tangled. The movie understands very clearly who the main character is and time away from her does not diminish the flow of the overall movie. The worst song in the movie involving the bar singers is done in the first act of the movie, and while being cringey and annoying, it propels the plot gently forward and all of the characters featured in it return in the Final Act.
Frozen 1/2 combined because I can. Movie does not know who the main character is and strains really hard to be true to roots and remain focused on the girl who is on the adventure itself, Anna. In the second movie, it suffers from the large amount of fans that Elsa have and in turn the girls must share the screen with poor results, namely that nothing in their relationship from 1 to 2 is resolved or taken care of. Both movies feature a cringe song (olaf and trolls in first, and Kristoff in second), but these songs are spread across the movie. Olaf's song and Kristoff's do nothing to help the overall plot of the story and weigh it down dramatically. The troll song, while sexist and rude, could pass as a more acceptable cringe song if it did not happen in late Act 2/start of Act 3, and instead took place earlier in the film (and we'd axe Olaf's song who the fuck needs that).
While both movies are made for girls, Rapunzel is shown to be curious about the outside world but able to defend herself in multiple ways including to but not limited to assessing her environment (the cliff and water fight). And she has actual hobbies for being a cooped up girl (the entire opening movie montage, most famous of which is her painting skills). Anna and Elsa have no hobbies or skills present in the first movie, or the second, while Elsa is shown to be overall smarter and better equipped. Anna is a bumbling moron who thinks she needs to prove how smart she is by climbing a mountain cliff, doesn't listen to instruction and jumps off a cliff to her death, and set's a man's cart on fire. Elsa meanwhile knew exactly how far away to get, and gets there very quickly in both movies and is shown to know how to defend herself. But again, neither girl has an ounce of personality. What does Rapunzel do? Artist. Tiana? Baker. Ariel? Antiques collector. Anna or Elsa? Nothing. Very akin to Jasmine oddly enough, a woman made for a "boys movie". What can Meg do? Master negotiator and queen of sass.
It's subtle but both Anna and Elsa do not rank any better than a damsel in distress character like Jasmine. Anna is only protected by plot armor in the second movie, and in the first she suffers from the Disney 'cannot kill someone' trope thanks to Lady & The Tramp scarring children.
Tangled is not a great movie either, but it continued the story acts presented by movies before it like Tiana's being amazing. How is Moana better than Frozen? The entire movie is literally about her desire to sail, learning how to, and being able to. Hobby and desire, done and done.
Act 1 of Frozen is heavy set up and dragging your feet waiting for action to happen. The time it takes for something to happen in Frozen, Rapunzel's already hit Flynn in the face with a frying pan. The difference with Rapunzel's opening, while about the same length, has constant knowing what's about to happen whereas Disney shoves in "so this happened, then this, this death, then this, THEN the upbeat song!" - telling vs showing. Frozen argueably doesn't start until the second song, about opening up the gates, is finished. Which by that point again, we've already sat through Mother Knows Best, and Flynn's frying pan bruise. We're on our way. In Frozen, we still have a coronation and party to sit through, then another song, THEN finally Anna leaves the castle to go look for her. I'd love to time it, but I'm pretty sure she doesn't leave the castle until 35min in.
Act 2 in both movies both feature the cringe song - Olaf and bar scene. But the real changes happen in Act 2 and Act 3. Songs in Tangled are basically done after the bar scene, with 1 small reprise of the healing song, and the start of Act 3 is kicked off with the reprise of Mother Knows Best. The action constantly happens. Act 2 in Frozen is choking to death on Olaf, sisters fight (best song), and the action of being thrown off a mountain, but then we get the second cringe song. Interestingly could be argued that the trolls are villains. In that same time, Elsa is attacked and taken to jail (man those boys sure moved fast didn't they).
Act 3 for both movies start off with a character in jail and breaking out. How it happens is different. Flynn is saved and energy happens like crazy as he rushes back to the tower. Elsa just like... does... something? We don't see it. We see the results, but they were too busy with the "omg let's make this guy in white a villain instead of the short evil keebler elf!" The only momentum we get in Act 3 is really only started when Elsa starts a storm and Kristoff sees. What's Anna doing during this? Becoming a popsicle and learning what the magic of love is - which is still wrong.
In conclusion, Disney should've taken the entire focus of Frozen and put it onto a single girl and the movie would be better for it. Anna's the more boring story, but they could have improved that. It suffers from the same issue as Wreck it Ralph 2- it does not have a focus nor know what it wants. Please bring back writers of Moana and Treasure Planet, ect. I only have seen Frozen 2 once and it's horribly disjointed. and sad that I immediately knew "that dam's gonna go" and the entire movie I kept asking myself "so when do the characters realize that?" It's painfully obvious that people in dev team were arguing about how much screen time Anna should get compared to Elsa. Do you go with your initial main character of Anna and make her interesting (lol no), do you include Kristoff and Olaf who are there just to say HEY IM HERE I EXIST, do you do the more interesting story about Elsa? No one wins.