In Formula One engines they’ve done away with camshafts entirely.
When it’s time for the engine to start, multiple sensors on the crankshat indicate to the engine’s digital management system where the crankshaft is, in relation to the engine’s firing order. A software map then activates pneumatic compressed air via solenoids to open every valve in the engine precisely the right amount per cylinder per compression stroke and voila! She kicks over.
From that point onwards until the session is finished, the valves are being blown open or blown shut by solenoids and highly compressed air stored in pressure tanks almost identical to a scuba tank. If your scuba tank springs a leak and runs low, you’re in trouble!
The system was first pioneered by Renault in 1986. Apparently Ayrtton Senna used to say that he could hold a given gear if he wished by an extra 2,000 rpm. The redline back then was 15,500 rpm. That was VERY impressive for the era. In that time, the engines are now nudging 19,000 rpm quite successfully for an entire race.
There’s no way that springs could handle such rpm without creating valve bounce. Well, in 250cc four stroke motorbikes they can, but when you get into 3 litre plus engines, your moving mass gets much higher and longer and the springs needed to spin 19,000 rpm would be gargantuanly big and heavy. So, a digital pneumatic system is the way to go.
Getting back to the OP however, Rick summed it up best. A nicely designed SOHC system can be a very, very reliable machine. It’s a nice compromise which produces good revs and good horsepower without a limiting degree of unreliability brought on by complexity. And there’s the rub you see. Engines like the Cosworth DFV were magnificent masterpieces, but they required regular rebuilds. That was what, 1968 and some 165 Grand Prix wins ago?
The technology isn’t new - with the exception of the pneumatic solenoid system - but the compromise has been easier to justify in terms of greater complexity these past 20 years due to greater levels of quality control.