It's all about the interfaces. More performant solutions require (in general) more complex interfaces.
If your application has grown as long as it could with the simple implementation, and now it is all too slow, chances are there's a lot of code depending on the interface. If your interface (and the implementation) is too simplistic, then all of that code will need rearchitecting, too.
If your application has grown as long as it could with the simple implementation, and now it is all too slow, chances are there's a lot of code depending on the interface. If your interface (and the implementation) is too simplistic, then all of that code will need rearchitecting, too.