My answer
I fully detail strip a brand new firearm to remove any excess packing preservative (grease, oil, etc.) and to examine the interal works. I do the same with any used firearm though I also add a detailed examination of all parts to make sure it is safe to fire.
I am OCD about safe firearms being a gunsmith and it really bothers me that some of my customers will shoot their firearms for years, perhaps a couple decades, without cleaning or any other basic maintenance. I have had hunting rifles of all action types come in with barrels that looked like a smoothbore shotgun barrel because they hadn't been cleaned for so long that the lands filled up. I have had others where the entire action and trigger assembly was stuffed full of gunk that it took several hours to fully clean the internals.
What I do know for certain is, I can go over 2,000 rounds of the cheapest, dirtiest .22 Long Rifle ammunition in my Marlin Model 60 and it still fires, though the accuracy is rather poor by then. However, as I generally shoot higher quality ammunition out of all my firearms I know that I can shoot quite a bit before most of them, generally mil-surp arms, have to be cleaned for actual functional reasons. I clean the barrels of my arms for accuracy reasons right before hunting season and fire one fouling shot before going afield.
Unless I am shooting hundreds of rounds in a session,I don't detail clean my collection, but I do check on their condition on a regular basis and I control the humidity in my homestead to reduce damage from that route. With self-defense arms I function check and spot check them on a monthly basis if I haven't used them for awhile.
I use common sense when it comes to cleaning, not too much and not too little. My standard is to remove or empty the magazine, quadruple check the chamber and remove the bolt (if bolt action), leave the action open and look down the bore to see what its condition looks like. Unless it is a precision or target rifle I don't worry about barrel fouling excessively. but if it looks like it needs a little TLC, it gets it.