It's called wifi tethering. Presently most devices working on Android 10 have this feature. You can also check OnePlus ,Samsung devices which have this feature.
"It's called WiFi tethering"?
You seem to be conflating basic Wi-Fi tethering with an extended feature of Wi-Fi tethering while making an inaccurate claim that most Android 10 devices use that feature. You might have also explained why we have different perceptions about it but before getting to that let's address those inaccurate statements before they get ingrained into readers minds.
Tethering does not necessarily include this ability. It might include it, but the definition of tethering is merely ... to tether. In our Android world that typically means a connection via Wi-Fi, USB, or Bluetooth but has also been used in the IT industry for a long time to indicate other types of connection. The ability to use the a Wi-Fi connection to the internet on the same device that hosts the Wi-Fi hotspot seems to be an extra feature that has been added to the basic function that we call tethering.
It is not the case that most devices, or even most Android 10 devices have this. None of the 15 or 20 devices I've used personally have had that feature including three devices currently on my desk which all ran Android 10.
If I'm wrong about the definition of tethering I hope someone will correct it but to the point of your observation, I use Motorola devices which may not have this feature. I'll do some reading about the one plus and Samsung devices that do this. Thanks for the tip. Do you, or does anyone know the name, the specific industry term, which is used to refer to this extended feature of Wi-Fi tethering?