Here is a quick guide on how you can make your iOS 17 Lock Screen look like iOS 7.
Firstly is the iOS 7 stock iPhone wallpaper.
Next is to use the new iOS 17 feature of changing the Lock Screen font and font weight (thickness).
Go into edit mode on the Lock Screen and you can adjust everything from here.
Choose the first font option and make it as thin as possible. I also recommend not using any widgets as iOS 7 did not have any. Select color to be white also.
Viola! iOS 7 Lock Screen on iOS 17! Enjoy 👍🏻