"Field stripping" a gun ....doesn't - in general - mean you are taking out the firing pin, firing pin spring, extractor ...in the slide on a semi-auto ...
let alone the trigger, mag release, safety, hammer, sear, etc .....
and when you fire a weapon ...there is a lot of carbon and debris that builds up in the channels where all of these pieces ride ...to make the gun function.
Even stripping the mags down is important ...its amazing how much junk gets in there ...( take spring out, follower, etc ) ...and clean them.
So Field stripping is good ...but its not a great way to take care of your guns long term. Parts that are dirty ....and moving ...do wear out faster than parts that are clean and properly lubed.
Some of us put 10,000 rds a yr thru our guns ....some put 1,000 rds ...so round count is part of the issue.
But if you like to work on things ..learning how to do it is easy. Its not a place where a bigger hammer is better ! Knowledge is important ..and every mfg of a gun has some things that are unique to their design / that make dis-assembly of that gun a little different. Sometimes its obvious you drive a pin out right to left / sometimes its not ...on some guns its easy to get parts back in upside down or backwards ...
But do what makes you comfortable ...not what I do / I like working on my guns ....I hate working on my cars / so I take them back to the dealer and pay whatever it takes. It would kill me to take a gun to a gunsmith .../ but that's just me ..../ at least until I've exhausted everything I know about the gun.
If you buddy breaks his guns ...its his issue / are they dangerous ....no, probably not. If anything - they will probably just malfunction .../ but its his eyes and his hands out there holding that weapon ...its his choice...