When do you ask someone to subscribe ?

I was just reviewing another channel and then once again it ended with the person asking the viewer to subscribe at the end of his or her video. Now there is nothing wrong with it and I am not here to tell you that method is incorrect but I have to say I think it is to mainstream to my liking.

I never asked anyone to subscribe on my channel two years ago and I am still going to do that now, why ? Because I feel like any dummy would know how to subscribe so your not reminding the viewer of anything so I really feel like if you like my content you would subscribe, sure I posted my content to my personal friends and they subscribed on their own.

Does it actually work asking the viewer to subscribe ? Is there any proof of someone creating videos not asking and the subscribtion rate is low and when they did ask it actually went up ?

Also is there some cases that you ask and some not ?

Maybe I am just a lot like my father. He started an ISP company and never advertised his bussiness went popular in our city through word of mouth. Now he is the best ISP in the city and cities around it where he started.

What is your take on this
I see your point lol, but people do this because viewers tend to forget and if they like the content they will sub, been a viewer of many YouTube videos I know
I just recently do this and I think I am not doing it right but still, I ask them to subscribe in the middle of my video. Viewers tend to forget to subscribe so you have to remind them.
There is no correct method to ask people to subscribe but we just say it at the end of out videos and put it in the description as a P.S..
Something simple- such as saying, "If you liked what you saw, subscribe to see more." isn't does far more than simply remind people. It let's them know that you're focused on continually bringing new, similar, content to their channel. If you post on a regular schedule, I'd say that as well. "Subscribe to see new videos every Monday and Thursday" or something to that effect. It doesn't come off as begging or needy, but helpful.
Having said that, nothing wrong with a visual reminder in the outro for people to sub. Although most people know how to sub, some will forget to do so.

I agree with you. I recently was viewing a tech video from a famous youtuber, and he pointed at the annotation while speaking to check the links. It just made me to at least hover and see what's that URL.

To answer initial post, as many told, its for telling people what to do. Personally I've seen many videos and I can see clear difference between creator asking to subscribe vs not doing the same. When I watch other's video, I'm a viewer for them, I can see how it influences what to do next.