One thing about a 90 deg V engine is perfect primary balance with no balance shaft needed.
An I-4, whether it's a single plane or cross-plane crank, still needs a balance shaft that requires energy to rotate.
The main disadvantage of the V layout is it makes the engine either tall or long depending on the V angle.
Also, once you change the V angle beyond 90 deg (plus or minus), you no longer have perfect primary balance, and now require a balance shaft.
In engineering there's never perfection, only compromise.