In software, you're guaranteed that 2 + 2 is perfectly 4 in an int32. It's a very clean abstraction. In hardware, operational amplifiers are affected by thermal

In software, you're guaranteed that 2 + 2 is perfectly 4 in an int32. It's a very clean abstraction. In hardware, operational amplifiers are affected by thermal noise, magnetic fields, parasitic capacitance, etc. It is not "incredibly simple", and although there are only a handful of inputs you /want/ to care about in that operational amplifier, the actual number of inputs you have to worry about increases dramatically as you chase performance, higher frequencies, and compactness. Processors must implement logic that can be represented by software, yes. However, when you're trying to push multiple GHz on nanometer technology, that implementation becomes especially difficult. I recommend picking up an RF engineering book, as it will only begin to describe the noise and side-effects that must be accounted for in those circumstances. There's a reason that Intel has physicists on staff. If hardware was truly easier than software, then we'd probably be building our web and mobile apps in that.