I mean, you don't have to use Investiture if you don't want to. It's literally just a setting element explaining how things work for the World Axis. It isn't a "rule" in the strictest sense. There is not, to my knowledge, any actual ritual for the process nor for its removal, that's all left for each table to figure out (or for adventure writers to write about.)
If you desire a different explanation, you can use it. But it would generally be best to stick with one that doesn't employ divine Big Brother surveillance, since that's rather well known for the problems it causes, both cosmologically and in actual at-table play.
And if one wishes to play a divine caster...?
Big Brother looking over your shoulder through the telescreen and instantly punishing your slightest heterodoxy isn't somehow the only way to run divine magic. Now who's "bak[ing] in a lot of setting information in order to make these elements work as intended"? Talk about a highly unverisimilitudinous way to go about magic. Major gods must hardly have any time for anything but watching their millions of worshipers.