Can cqb be evaded?

I was talking with a buddy and we got to cqb.He says that cqb is useless and there's no reason for it.After some arguing he then kept explaining that on a Frontline you don't need cqb and it's pointless,you should just encircle a city and let it starve or surrender,I tried explaining that it is a good tactic but eventually you will get into one,you can't just guard a city until starvation.Since cities are objectives/key positions you need to get into them and can't just bomb/arty them because there are civilians etc.We got into this subject because we argued that he said full auto is better than single fire in cqb.I prefer single fire and to control everything I do,he says that full auto is the way to go,shoot through walls and obliterate everything.We are both civs but I'm a military enthusiastic/airsoft player so I know a tiny bit of stuff.From others experience/perspective whats the best way to do cqb and why do we still practice it?

(I told him cqb may not be a good idea in a full scale war...(In his perspective)... but is still forced in urban terrain and law enforcement,he just changed the subject to full scale war and Frontline)