A cloverleaf requires more width to fit. The highway right-of-way may not be wide enough, or the width may have been “eaten up” by widening the highway. The more lanes going through, the less room on the sides for exit ramps.
The cloverleaf doesn’t need any stoplights so in theory it should have the best continuous throughput. However it does require mixing lanes, which can lock up more easily under heavy traffic than separated sequential exit and entry lanes.
It turns out that engineers select different interchange designs based on the expected traffic patterns, and there is no one-size-fits-all method.
As a sidebar, my dad was part of the (huge) team of engineers that helped implement the first few diverging diamond interchanges, and so its a fun reminder of him, even if I'm not on a road he had any hand in designing.
It’s basically introducing a bunch of traffic lights where none would be needed with other designs.
The truth is that the standard cloverleaf is way superior but they’re cheaping out on land or construction costs and trying to pass it off a better design.