you'll probably get more replies in the things section than here. Here people mostly ask about manga related stuff like recommendations and trying to find specific manga. Sorry I havent updated so I can't answer I just wanted to redirect you to where you'll probably get more answers
this is my opinion, please take this with a grain of salt.
Newer ios takes a lottttsss of space, so if you're using 128gb phone, I don't recommend updating.
And there's also mobile data problems. Some experience issues with mobile data, which they can't seem to use it unless they put it on roaming but they can use wifi perfectly fine. This usually occur on pro and pro-max series (based on my observations). And ios updates usually slower your iphone because it might not be compatible with your iphone's motherboard (take 13's for example) and might take a toll on your iphone battery.
The pros is the user experience, its nice– easier access to certain things, like previews, games applications where we can see our game lists etc.
what are the pros and cons? im planning to updateee