AITA for leaving a group chat after my friends kept making and cancelling plans?

I 29F was recently added to a small group of my friends’ big group chat. This was a group that formed around mountain stuff, basically hikers that wanted to go farther than the average person, started by “Brenda.” 

I already do lots of hiking stuff outside of my friend group, but I was down to do more with the more serious ppl among my friends. 

First, Brenda initiated a backpacking trip and i was really excited. We planned it over one month out. One week before, she had made some mistake with the permit, and it didn’t happen. OK. Stuff happens.

Then, we planned a smaller day trip with two cars. The day before, Brenda’s car had issues and she said we should reschedule. OK then. 

The third trip rolls around and again, one week out, Brenda says, “I actually don’t think we should do this one. What about this one?” and proposed a new date and place. 

I had enough. I texted the group, “Hey guys, sorry I am too busy right now to handle this group. I’ll see you around!” Brenda immediately texted me and said it was rude for me “abruptly" leave and that "nothing needed handling." I asked other friends and they said I was being uptight about just some texts. For me, it feels disappointing to have things moved and canceled so much so I left. AITA?