It sounds like you're talking about making an equivalent of Super Mario from the 80s, but modern games are in fact much more complex.
And no, just because people in the 80s enjoyed Super Mario doesn't mean it's the pinnacle of game design, and that there's no need to create anything more complex.
> It took less than a month of work for me to get a polished cross-platform system working on five platforms.
You simply don't know where the bugs and performance pitfalls are because you haven't encountered them, yet. That is especially true regarding consoles with their custom hardware and mobile devices with their abundance of cheap, often not well engineered hardware and sketchy drivers.