I don't think this is correct. Top PS3 exclusives (Uncharted 3, The Last of Us, God of War 3, God of War Ascension, Killzone 2, Killzone 3) were 720 p, GT6 was even 1440x1080, and that was racing game with top graphics on PS3 and in 60 fps. Top Xbox 360 exclusives (Gears of War 3, Gears of War Judgment, Halo 4, Forza Motorsport 4, Forza Horizon) were 720p. Almost all top multiplatform games for those consoles were 720p or very close to that.
About 540p on XSX/PS5. I said some 5 years ago (and many disagreed with me), what all this simplification in hardware and software will not lead to anything positive. I'm not trying to say I know something better than anyone else but I had and still have this opinion. When consoles were harder to programm, and there wasn't much or any automitic processes in development, developers could've achieve better results. They worked hard, but improved their skills, when programmers wasn't able achieve something, designers or artists was able, thet lead to more interesting and even experemental ideas to games, (of course that wasn't always cool results
but still). This is like in my work, here are moments when I should do something harder, but results after that is better, and when all goes by standart system, it's just routine and sometimes results are basic and even worse.