No. You are talking nonsense. You are the one suggesting manufacturers purposely make AV receivers deeper than they need to and you are the one suggesting it would be cost effective for them to do something they already do that doesn't solve you issue, but as an option for every single one of their existing receivers.
Sorry, but what system are you refering to and which aspect of its design? You really want me to start getting technical with you? According to you its simply a matter of housing microchips, but what microchips are you referring to? The DSP chipset, the video processor, the DAC etc, etc, etc????? What about signal paths and avoiding signal cross talk and what about where you put things such as inputs and outputs relative to the power supply?
Suggesting I'm stupid without actually having any understanding of what is required yourself simply makes you more stupid than I am.
Rants? I'm explaining myself while you're daydreaming. What is it you are now awaiting, a manufacturer stumbling across your thread and making you a bespoke solution for a budget price? Good luck with that one. The answer is no, there's no AV receiver as shallow as you'd like one to be and there's not likely to be one in the foreseeable future (for the reasons already explained)