On the other hand, when TNG first aired I found it to be a huge let-down on the story and character side. All that shiny new tech and it's full of pod people.
TNG was a step into a different direction, started by the movies. I doubt Star Trek would be as popular today if they kept TOS style.
Yeah, TNG did a lot wrong, starting with the insistence that each episode has to stand alone and its self-indulgent incestuous writing. Some of it got worked out later on, a lot of it stayed. But it certainly revived the franchise and paved the way for some of the best stories in the franchise.
You can imagine it as this
TOS - The first experiment gone popular, drew the first people in
TAS - There was an animated series? Yes there was, an extension of TOS, it was more of an experiment gone wrong, and only lasted a couple seasons. I would watch it, but as an occasional gag, not as a serious watch.
TNG - Brought major popularity to the series. It was the first experience of Star Trek for most, and was designed so newcomers would get hooked. Having the episodes being separate stories was more of a choice to make sure that anyone could click on and just start watching. Some might find this annoying, but I do not.
VOY & DS9 - Where the series got good. To me these are where they tried different formats, and it appealed to the original crowd they drew in. It was my second set of series I watched, and let me tell you I was happy I did. I love these series, and while TNG is good for watching any old day, when I am binge watching I normally flip to these.
ENT - An underrated, yet flawed series. It had a load of crap with too many episodes being dedicated to pretty much the same thing, making long boring episodes. It did have it's gems though, and there were interesting episodes without a doubt.
And another word. Every mirror universe episode SUCKED among ANY series. It was just stupid.