Well having this ability to archive wallet address makes it simpler to find addresses in wallet that you want to use
You don't normally 'find' addresses in Bitcoin Core. You generate new ones when you ask for one. It does not normally give you a list of your own addresses.
This could free up resources used within client or loading time. If someone has tuns of addresses in it and has to rebuild or load up
Resource usage per address is very neglgible. Even with tens of thousands of addressees it doesn't take a noticable amount of time.
and if one of the old addresses receives payment it then gets auto shifted to active and a little notice popup saying you received payment on archived address that has now been made active.
Well if it does that, it's not actually deleted!