I have no nostalgia to earlier editions of D&D - I played other systems, and then stopped in my teenage years. I played Baldur's Gate, but enjoyed it in spite of the weird maths. I played Neverwinter Nights, and enjoyed it too.
I have always been D&D curious, and as a (much) older person I resolved to try it out again just as 5e came out. I thought it was great, because finally I was playing D&D in real life. I ran 5e campaigns, and played in 5e games. In the last three years, my gaming group has grown tired of D&D. We want to tell other stories, and while we can do so in D&D, there are so many systems that are better at telling the stories we want to than D&D. This isn't a problem with 5e, more a problem with the framework 5e has inherited. It is too idiosyncratic for my tastes - there are too many legacy elements that exist because of previous editions, too many assumptions of how X should work, too much baggage. The fans are passionate to the point of self-destruction, for they are all passionate about entirely disparate things that are all at odds with each other but are all intrinsically D&D.
5e is an excellent D&D. In my humble opinion, by far the best D&D. But it is D&D. It cannot handle much outside of the scope of D&D. I have enjoyed it, and I wouldn't say no to playing it again, but I and those I play with are playing a wide range of other systems which suit our needs better.
The next iteration is far less courageous than I had hoped, so I may buy it out of habit but my interest in it is academic rather than heartfelt. I am fine with this - people who want D&D should get D&D. I wish them well.