I don't think I've ever switched off an episode of Friends once I've run into it while Channel-Surfing. The actors just have so much chemistry. I still remember all the words to that opening song as well. I even remember the music video they all made together in the 90's.
Another thing to keep in mind is that once Netflix got the rights to the entire series it immediately became one of their most streamed shows that they have to offer on their service.
Friends was a formulaic comedy that relied on solid character development and well structured story lines to carry the show. It wasn't especially ground-breaking or revolutionary, but it had a solid cast and allowed all the characters to be likable in their own way. Again, the humor was revolutionary, but it was solid every week.
Yes, Friends is a good show. It has a good cast of actors and a well-defined set of characters. It's funny and each actor gets to shine in the light at some point. In addition the characters exhibit positive qualities such as a desire to look out for each other. All in all, it's a pretty good show.
It was very popular during it's time, but it is fairly bland. The charcters are are all white Middle/upper class people and it is hard to see why it was so popular. Clearly it appealed to some people, but if you were not a fan then you problably aren't going to be a fan now.