I really like 5E, but somewhat agree with you. To me 5E is the "B+ edition" - good to very good in most ways, but neither amazing or bad in any way.
And the vanilla analogy that someone else rings true for me, as long as we say premium store bought, rather than supermarket brand. And to this point...
Yes, this is exactly it. If you can only ever buy one flavor of ice cream, it should be vanilla because not only does it go with cake or pie, you can always add toppings. Super Dooper Chocolate Caramel Chaos may be tastier, but it lacks flexibility...it doesn't go so well with strawberry pie.
But that's just it: It is stronger now than ever partially because of the glacial pace. The tortoise approach is working.
That said, it does seem they are upping the pace a bit. From 2015-17 they released three books a year; last year they added a fourth; this year they are releasing five if you include Acquisitions and the Tyranny of Dragons book, not to mention two starter sets in Stranger Things and Essentials.
Who knows what next year will bring?