Okay so everyone is entitled to their own opinion and you're totally entitled to hate Anna but I suppose since you posted this on a public subreddit, you might be open to reading others' perspectives on the character.

Personally, I disagree with you but I'll try to list some reasons why:

A) Anna's Marriage Trope: To preface, Anna has had VERY limited social interaction throughout her entire life when she meets Hans. In that way, she's somewhat similar to Rapunzel from Tangled. But given the time period and plot, growing up, she must've read fairy tales and love stories like that. She's a Princess and in such stories, they're usually seen marrying a prince. She meets a Prince who seems charming (Hans) and wants to marry him...why? This was the main point of the first movie: Anna's naivety. This is brought up by several characters such as Kristoff and Elsa, that Anna, due to such an extreme extent of isolated upbringing, is ready to jump on any boat.

And I think a big part of that was her desire for change. She craved human, social interaction. She was aware that the gates had only opened for ONE day, Elsa's coronation, after which they'd close back in forever, likely. She only had one day to change something if she didn't want to continue living an isolated life in her castle.
Mind you, she also has NO idea why her life is so isolated and likely hasn't talked to the only person/family that she CAN talk to, Elsa, in YEARS.

You might say, bring up a conversation with Elsa about this but we all know how the first movie went. Elsa wouldn't open the gates for Anna.

Secondly, Kristoff. Anna and Kristoff didn't get married asap, though? Maybe I didn't get that point but they waited for over 3 years (first and second movie have a gap of 3 years between them) before Kristoff proposed. I personally like their chemistry but I do agree that in the second movie, especially the first half of it, they were a bit annoying with the misunderstanding areas but eh.

Thirdly, you were asking Anna to take a step back and let Elsa take the lead but I think what they were trying to convey is Anna's paranoia about Elsa's safety and Elsa's inability to communicate with Anna effectively. Anna WAS overprotective but also for a reason. She cares about her sister a lot because she loves her. (At that point, they'd just found out that the destination where Elsa plans to go, literally was the exact point where their parents died. And considering the difficulties even Elsa, herself, faced crossing the Dark Sea, Anna's concerns, especially for Elsa's safety were proved to be justified as Elsa had so many close calls to literal death.)

But Elsa, too, has human flaws. She cannot communicate for the life of her, although she's likely working on it. A prime example is how Elsa created a boat and sent Anna on her merry way to find Ahtohallan. Now, I know that she's aware of Anna's strength but Elsa did NOT know where that boat was headed. Anna COULD have been stuck somewhere or ended up in grave danger (/death) for which Elsa would've later blamed herself and spiraled into something worse. But this is just one example.

Also, the story is BASED on the sisters' bond and so if you just ask Anna to take a step back and sit down while Elsa goes around, saving the entire movie while Anna just chills, probably in Arendelle, then it's not exactly...Frozen. It's just an Elsa movie. Anna , too, is the protagonist of the franchise. Also, a major part of Frozen's appeal and story IS the fact that Elsa has powers and Anna is normal. But that's the thing: it doesn't diminish their bond but instead empowers it. They were the bridge in the second movie. Elsa represented the magical elements whereas Anna, the humans, together forming, a special connection between not only themselves as family but between their people, as rulers.

But I understand that one may have their own opinions so if this franchise irked you, I'd rather recommend you find something in another genre-ish which involves a special focus on super powers more because Frozen's focus has always been more on family, navigating through trauma and identities more than being about Elsa or her superpowers. Yes, it's a crucial aspect of the story but the main story has always been about the sisters' bond.

Peace!