Will I have to log into my apps again after setting up a new iPhone?

It really depends on the app. Some apps transfer automatically, but others, especially banking ones, usually require a fresh login. So, be ready for some manual logins for those specific cases.

Yeah, it's a bit of a mixed bag. Most Meta apps like Facebook and Instagram are usually transferred seamlessly. However, apps like the Ring app and anything under Google's umbrella often need you to log in again. Generally, I’d say around 90% of my apps retained login info, but a few made me re-authenticate when I opened them.

If you created an encrypted backup or used Apple's setup tools, you may stay logged in for most apps. But some will ask you to log back in. There's also a tool called MobileTrans that might help keep more of your app data intact between devices, including accounts.