Re: Innovation? We've heard of it
Your not talking about Amigas and it's applications then as that was C and linked libraries and functional GUI elements. Yes games would dump the OS, multitasking and hit the Hardware with probably a fair bit of assembly.
Modern compliers will generally produce quicker code than hand assembly unless there are some major cpu instructions the complier can't use like SIMD. Most of the time you'll be slower.
The problem is more likley (in no order):
Bling GUI elements like transparency, fade in and zoom on to display or wobble.
Text based protocols and formats like HTML, XML which has to be scanned byte by byte.
Can't even tell how many bytes a character is with checking each one, but it mostly doesn't matter.
Use of Frameworks where 5% of the features are used but have to take the hit of the complexity of the other 95%