I dunno, you seemed to ignore the "at similar settings to a Switch" part of my comparison. I do not believe for a second that Skyrim at 2 hours is the same settings as Skyrim Switch which would I assume get around 2 hours on the Switch.
Yes you need to limit TDP and FPS to get super long battery life, but that's just a tap or two away, it's built right in to the OS, which I argue means it's fair game when looking at battery life.
Sites like SteamDeckHQ exist for the sole purpose of reviewing games on the Deck as a portable device where you'd drop settings and framerate to get those 6+ hour battery life times on more demanding games. Sure on a Deck you CAN run it at 60fps and better settings than the Switch, but you can also drop those settings and double your battery life as well.
Like Octopath Traveler on the Switch is 30 fps. And low/medium settings too. On the Deck it runs at 2x the framerate, no drops, 60fps, with all Ultra settings. And battery life is totally fine. But if it's not enough? You can limit it down to Switch settings, and I'm sure it'd do better than the Switch.
Are you just playing these games at max TDP? I get more than double your battery life in Yakuza at 60. It doesn't need 15TDP.
Its not to compare it with a switch 1. To be honest, switch 1 is a generation older then steamdeck. Its 5 years in between. Im sure the steamdeck battery life is better as a switch 1 when you downgrade a more demanding game to run it like it does as a switch. The point is that newer games or games specially been used for the hw it has, the battery life is not that good.
Tests were executed having 90 fps. I did copied it from a site who tested the steamdeck og (60 fps) vs stemdeck oled (90 fps).
For playing older or tweaked games by lowering the settings (lowering what it actual can do), then its fine for its time. Its like what nintendo did with the tegra chip to gain battery life. Nvidea is really good in power consuming compared to other companies.
Specially with their mobile chips.
I dont see it as possible to run ps5 like games on a newer steamdeck having a decent battery life within 3 a 4 years from now as pc hw isnt build for that kind of thing. Even laptops with a greater space for a battery is mostly not great with new games. But again, you can downgrade them to improve the battery life.