Also, why can't we just have a fucking shelf or a bracket.
Ever since radios stopped being a standard rectangle, and the dashboard was filled with kevlar sacks and explosives there's nowhere to put anything down.
As of 5-6 years ago some (many? most?) cars still had a good old standard double-DIN slot for the infotainment unit, if you popped off the dashboard's plastic cover.
No clue if that's still true; I think it has become less true over time for sure.
There are benefits to automakers for retaining that standard form factor. Most factory-branded infotainment systems are made by a handful of OEM manufacturers like Bose. Bose makes systems for multiple automakers. So the double-DIN form factor has persisted, it's just hidden.
Problem is, for most cars, the climate controls and shit are all bundled into that infotainment system. So you can slot a standard double-DIN stereo into most modern cars, but you need a replacement dashboard panel and fairly elaborate kit to replace the OEM climate controls and whatever else.
Ever since radios stopped being a standard rectangle, and the dashboard was filled with kevlar sacks and explosives there's nowhere to put anything down.