Ubuntu targets a LOT of different hardware, it would be much harder to optimize the layout on their ISO image than it is to optimize for a fixed hardware platform like consoles.
We also have pretty amazing hardware today that is surprisingly underused most of the time.
I've seen many Unity projects with the worst code you could imagine still run close to 60 FPS when shipped.
Having an easy entry point means you're also going to get a lot of mediocre programmers using it. They seem productive in the first few weeks of the project but then quickly slow down halt once they start changing the design and end up with massive overtime hours while trying to debug and optimize the resulting mess.
Its made even worse with managers trying pseudo-agile-learned-in-a-two-day-masterclass adding even more procedures and overhead.
So yeah, you can make games today with less development talent than yesterday, it's still going to cost you more than having skilled software engineers and the resulting product will be a fraction of its potential.