Installing addons/mods

After downloading many addons I’ve started to wonder why installing many of these gets to be so aggravating. About the only things that I’ve found very straight forward are things for the adv. duplicator. Why are some put into the addons folder while others have you copy the lua,models etc themselves to the garrysmod/garrysmod folder? Also I noticed how many that actually do have where or how to install just don’t work. Are there many of the downloads that just don’t work or perhaps does it have to do with maybe conflicts with other previous downloads? Why isn’t it more common for people that create these to actually put the few sentences to tell where or how to install? I often run into downloads that have no such description and will see someone ask the simple question of where to put the files in the comments, only to have someone tell them they are idiots and as such should just go away. I guess I’m just wondering why there isn’t just a more uniform way to get these installed? I personally don’t play this but do this for my son who is a bit tech challenged. But years ago I did dabble into some mods for games. What I would do is add a batch file which people could use to seamlessly get the mod to install properly with no problems. Is that not something that could be done with these? Sorry for the long somewhat babbling post. Thank you in advance to anyone that might respond and shed some light on this subject.

Case in point that nobody reads. There are multiple threads, posts and websites that explain in great detail how to install everything. It really is simple…

No info.txt = extract the stuff into the garrysmod directory (Lazy ass author)
info.txt = Addons