Honestly Drupal is solid for a number of things, and in terms of getting a CRUD type app/site up it's probably still one of the fastest ways to do it for the non-technical. Actually pretty cool that you can get APIs straight out of the box this way.
That being said, Drupal was initially a forum/blog and it definitely seems somewhat out of place in the modern web landscape. One of its Achilles Heels is that its rendering layer is notoriously slow and overall it's heavy. It's module system also doesn't mesh well with PHP's typical request/response execution model from a performance perspective (anyone who's spent time tuning PHP opcode caching for this knows what I mean).
That being said, the content type and field system is still great and it would be great to see a more generalized version of this concept. This is another area where the implementation is pretty heavy on the Drupal side. Things like this have ultimately limited adoption and not having a clear migration path from D7 to D8 didn't help either.