So, theoretically you can use your computer in it's current state for as long as you want. I have gone 60+ days without updating (it was an experiment and I wanted to see what, if anything would break, and I was learning how to fix it.
Eventually, as long as you use that system and are planning at SOME POINT to update - you will need to merge the pacnew file at the very least. In it's current update process, the pacman update will break pamac.
Leave your computer exactly as it is forever. (there's obviously a LOT of reasons why you shouldn't do this, but, it's your copmuter).
Update, merge pacnew, learn how to use pacman and yay/paru instead of pamac.
Reinstall your system everytime there is a major update that requires manual intervention. If you always have a new system - you never need to update.
Use a different distro that doesn't require manual intervention or any real involvement - Linux Mint has automatic downloads for instance. Solus is rock stable. Debian. .. . just never changes.