[bebna]

If you mean emulation on handhelds:

Multiple vendors with multiple new models per year, different quality and price levels. Some come with Linux based systems others with android or even Windows. So you can choose between a selection of models for roughly 50-100USD, 150-300 or from a section that is even more expensive than a steamdeck but also provide more on some or all fronts for they bigger price tag.

There are some devices that are basically the same concept, just in new generation, but there are also many that are more unique. The space seems to require it, button layouts or screen ratio / resolution play a mayor role how well the emulation experience is, but there are so many different consoles over the years that they can't just do one thing fits all, especially if they want to keep it a handheld or sometimes pocketable. There was just a windows device released with clamshell dual screen design like the DS, but thicker to run basically everything on a modern AMD Windows setup.

The portal wasn't an unknown device in that bubble, bc some people use there emulation handhelds for streaming, as in in-home streaming or like the nvidia shield, cloud gaming streaming, often Xbox game pass these days.

There is a whole section of controllers that make a smartphone a portal/switch/steamdeck like device, by holding it in the middle and connect via usb c, lightning or Bluetooth. There is a good set of emulators for phone, snapdragon is quite good in emulating switch for example, but there is a also next to streaming, android native games that support controllers or apps that produce virtual touch inputs to map the controller.

There is also a scene that makes handhelds like the DSi, psp, vita, etc emulators who work quite well if you want to put in the effort to set it up.

I recommend retro game corps on yt for a start, he doesn't do quick bait or mind numbing flash cuts.