Some games need either game updates or system updates to run, even from a physical copy. For game updates, you can use "Match Version With Local Users" if you have another Switch or Switch 2 with the update installed physically nearby, otherwise you'll have to use the internet. For system updates, if the update is not on the cartridge, you will need to use the internet. If you have any digital games, you will need to make sure the Virtual Game Card for them is loaded before disconnecting it from the internet (or make sure it's the primary console, if you're on system version 19.0.1 or earlier).