The problems with ERP is (1) in order to be a big player you have to cater for so many use cases it starts becoming a glorified development tool without any room for providing actual ROI to the vertical that wants to buy it. (2) it's very, very easy to fall into the trap of saying "well, process x is really no different in industry y, we can adapt the ERP system". In reality there's so many nuances that the platform becomes compromise.
Vertical specific software provides so much more value as you can build things unencumbered by the engine/data structures/way things work.
I've found our niche - ERP's would be hopelessly expensive so save for top tier OE companies no one uses it. In weeks we can develop and roll out features & functionality that our clients just lap up that you would never in a million years build into an ERP platform, but is intrinsic to the delivery of our clients products.
It was inconceivable to me 2 years ago, but now I've had very real discussions with some companies where they're looking at our software going "wow... you're going to give mid tier players better functionality that we could only dream of from our ERP systems.."
Basically ERP platforms are "jack of all trades, master of none".
In my former life we did vertical specific software for the window and door industry. Every time we heard from a prospect "oh we're looking at __some ERP platform__ to do configuration of W&D", we'd immediately list dozens of reasons why they would fail, and fail hard.. countless untold money to consulting teams has been burned learning those lessons.