Computing is like an iceberg, with the web being the bit above the surface.
rich enough that you don't go bananas solving large, interesting problems [assembly]
Two words: macro assembler. It may surprise you to know that not that long ago, sophisticated GUI apps were written in assembly language (in fact the IDE I use on my ST, Devpac, was written in assembly, and it's everything you would expect of a modern IDE - editor, compiler, debugger, etc - running under GEM). Many games were written in pure ASM.