Switch is a great little system will end up one of the most popular consoles of all time. Admittedly I think of it more in its handheld form since my boys have Lites and I never played docked when I had a V1 many years ago. It’s more streamlined in that regard compared to the Deck.
In your comment it made it sound like Deck was just about graphics while the Switch is about games. As a Deck fanboy I just wanted to chime in about the Deck’s amazing game library. All of Sony’s games have been Deck verified, I’m dual-booting so I have native GP+EA Play, there’s niche cult hits like Elden Ring. Deck has something like 6000 verified or playable games not including Windows or emulation.
There are some games where the fact they were optimised for the Switch brings better UI and default controls compared to the default on the Deck. Also for some games the screen quality, if you are lucky enough to own an OLED Switch, means that the game is much more impactful on Switch (think about a Diablo 2 remaster for example). Also you have the Nintendo first party games, that goes without saying, but their quality is overall so good that you have to say it.
With that said… Steam Deck (which is ergonomically better than the Switch IMHO: fits well into the hands without giving cramps, has symmetric top aligned analog sticks, tons of inputs including back buttons and touch pads), even without dual booting into Windows (which for now it is the only way to get your HW accelerated RT in games, yeah I know it comes with sacrifices hehe), has an incredible amount of games supported with either no user customisation required or many that need minor changes SteamDeck allows you to do using super user friendly UI (they made the PC modding/customisation in the software side experience so much more user friendly it is. It even funny

). It is the best game launcher by miles.
If you want to play modern games that can run on PS4 HW you can have a quite great time on Steam Deck even putting them on a decently priced SD card instead of the main SSD (you will not find many issues with loading and streaming considering the games were built for HDD’s with similar or lower throughput and much worse seek times/latency)… so you have a lot of stuff to choose from between modern console and PC games, indies, and PC classics (that still get modded and improved).
With a very very simple step through desktop mode you can install Luxtorpeda and easily customise the launcher used for the game (welcome ScummVM for many games, welcome easy OpenMW installation for Morrowind, etc…). Want more? No problem, you can push a bit more and setup mods for games using desktop mode as a PC (hello NorthernUI mode with gamepad support for Oblivion).
Between official custom SteamDeck gamepad to game controls mappings offered by the game developer, Valve’s own default templates, and community provided (and rated) controller mappings (you can download, customise, and republish too

!!!!), the sky is the limit (per game profiles).
Then you have easy to use performance profile tools (super trivial to get an FOS counter on screen) and the ability to setup per game performance / battery profiles super easily too: the ability to set the screen refresh rate to something between 40 and 60 FPS and limit framerate fixes stuttering and tearing: many games are perfect at 50 FPS, they are not noticeably worse than 60 FPS and can spend a considerable frame time savings in better visual fidelity (or even 40 FPS)… it is not dynamic variable refresh rate but it is not a display that has a fixed refresh rate, you get control and it is easy to make it a better experience for yourself. It would be nice to see console games licking to 50 Hz on modern TV’s instead of 60 Hz…
Did I say that symmetric analog sticks are still the best and having them on the top of the unit (instead of both at the bottom) is a great compromise between the two sides of the battle

? Ah repeating myself hehe, just so glad they went with this setup.
If you wanted a PC in your hands (you can still connect to the TV) without a lot of the pain taking advantage of the customisation and freedom of the platform normally brings you… this is your baby

. Ok ok… you could also get an AyaNeo2, but I think you would miss some of the control options this puppy has (but yes you get a faster unit and a better screen… although I will always defend the 1280x800 resolution and aspect ratio, great compromise for modern and classic games… big display and not crazy high resolution is also good for my eyes and avoids scaling issues for older games).