Also Better hardware =! better games. There is a reason why Nintendo games keep selling even if their hardware isn't "up to specs".
But it has better hardware AND access to better games. MORE of them and far cheaper too. Not to mention in their better version out of the two.
I give a quick look at my library on Steam and before even beginning to consider spending any money I already have ready to go:
Any Souls game or Sekiro, played at 60 fps.
Slay the Spire
Blasphemous
XCOM 2 + War of the Chosen
Psychonauys 1 and 2
Nioh
Divinity Original Sin 1 and 2
Battle Brothers
Ori 1 and 2
Hades
Furi
Metal Gear Solid V
Any Batman Arkham game
The Witcher 2 or 3
Spyro trilogy
State of Decay
etc.
I could go on for a few hundred titles (no, not a hyperbole. I could LITERALLY list hundreds I already own) and that's selecting only the small percentage of my current library that seem REALLY well suited to play on a handheld device.
"B-but SOME of these games are on Switch too".
Ok? But I already own them and I'm not going to pay the "Nintendo premium" to purchase them again, so I cam play their shitty downgraded version running at 20 fps on a Switch.
Not to mention a Deck can also pretty much overalap with all the Nintendo first party output up to this point in time, bar a couple of titles that still have shaky emulation. Breath of the Wild and Mario Galaxy on this device will run circles around the Switch version, for instance.
Anything Wii U related or lower will run smooth as fuck too. And then there's emulation compatibility with OTHER consoles, like the PS2 and PS3 etc.
People can keep giving Nintendo the mouth service all they want and use VICARIOUS BRAGGING about its sales all they want, I don't have particular doubts on what device of two will be more appealing "for my user case".