They are, in almost every way, taking the console model approach. Updates when there is a significant generational leap and not just yearly updates because AMD made a slightly faster APU (though they did the switch to switch OLED thing but no one complained about that because they kept the LCD models for sale and the OLED really is nicer), selling at a loss (and making up for it in game sales) and of course, the ease of use that a console interface offers over a traditional PC interface.

Then they step it up beyond that by making it as open as possible (software/emulation, games from any source, it's really a PC) and making the hardware repairable (making parts available and easy to fix in the first place,) and of course, cheap games and practically every game you'd ever want.

What the other handheld PC companies are lacking is (with some exceptions) repairability, that console experience, and price. Us nerds that can do whatever with technology will do it, so a legion or an ally or a gpd will sell just fine to that demographic, especially for the frame rate chasers. But for most of the rest of people, they would just get a switch or a PS5 or Xbox because it's just plug in and game, and at least in the case of a Switch or Xbox S, the cost of entry is way lower than a PC, be it a gaming desktop/laptop, or even many of the handheld PC competitors. Yes you can build comparable cheap PCs to an Xbox or PS5, but that means building a PC, and most people don't want to do that (I'm not talking to you, I know you have a sweet rig.) Yes I know games on PC are usually cheaper especially Steam sales or key seller/bundle sites, but console gamers often don't consider that, and initial cost of entry is very important to non-enthusiast type people in any given hobby.

There's a reason why Nintendo consoles sell so well despite being behind the competition in raw horsepower. It's the console model (and in their case aggressive exclusivity of their famous IPs)

The things keeping Sony and Microsoft in the competition are basically the console ease of use, and their all you can eat subscriptions. Even they both realized that they can get more sales putting their games on PC, but that still means forking over MSRP for a single game, so those ps+ and gamepass subs are keeping them afloat at this point.

I'm a huge tech nerd and have been deep in related industries for over 20 years. I know how to do whatever I want with any pc hardware or software, I own a steam deck, and a rog ally, a proper beefy gaming desktop, a gaming laptop, a Switch, and a PS4. Despite all that, in the past 2 years, easily 90% of my gaming has been on the Steam Deck. It does everything I need it to and more, and it does it anywhere, anyhow. If I want to tweak and tinker with it I can, but more importantly, I can just PLAY GAMES with almost no friction. At home, on a break at work, at the airport waiting for my flight, cozy in bed, wherever, whenever, and fast, and easy.

The Steam Deck is the swiss army knife game device that childhood me always dreamed of, and now it exists. That is why it's outselling it's competition, and genuinely making PC gaming a viable thing for the masses. No it won't beat Nintendo anytime soon, but it's gaining steam on them and other consoles faster than any other attempt ever has before, and it will only get better.