In my experience, a bore snake gets about 80% of fouling. For a quick clean, or when breaking in a new rifle barrel and I want to clean it every 5-10 rounds, that's good enough.
Good enough is probably enough for most folks. Many folks don't even clean their guns properly, and a bore snake is far better than neglect, or improper cleaning.
The use of harsh brushes can damage the bore. Abrasives can damage the bore. Cleaning rods contacting the crown can damage the crown and reduce accuracy. The difference between new, and worn out, is a few thousandths of an inch. Doesn't take much to wear down a crown through poor cleaning habits.
So, excessive cleaning, or improper cleaning, may be more of a threat to a gun than not cleaning.
A lot of guys clean too much.
For example, the M1 Garand runs clean. The gas system ejects the gas up at the forward hand guard, so the action stays clean. I clean the bore after every range trip (100 or so rounds) but leave the action until at least a year, or several range trips (1,000+ rounds) because removing the stock to clean the action compresses the wood, and causes the fit to degrade, degrading accuracy. Cleaning the bore on that rifle, because of how the receiver is built, means bore snake or muzzle guide, as a breech-to-bore cleaning can't be done. I've played with the Otis pull cord cleaning system, and similar to a bore snake, that seems to work pretty well.
In the old days of corrosive ammo, you had to clean that day and clean thoroughly, or the salts would rust out the bore. That's not really true anymore, so, while I like my guns cleaned and oiled before they get put away, that's preference, not a requirement.