Can uvc-gadget can go up to 4K on a Rasperry Pi 4B?

Question

I want to know why this tutorial for the raspberry pi cameras can't go up to more than 1920 x 1080p ? The camera module 3 can do 4K, as well as the HQ camera that works with this tutorial.

What has to be understand with this code ?

#!/bin/bash

# Variables we need to make things easier later on.

CONFIGFS="/sys/kernel/config"
GADGET="$CONFIGFS/usb_gadget"
VID="0x0525"
PID="0xa4a2"
SERIAL="0123456789"
MANUF=$(hostname)
PRODUCT="UVC Gadget"
BOARD=$(strings /proc/device-tree/model)
UDC=`ls /sys/class/udc` # will identify the 'first' UDC

# Later on, this function is used to tell the usb subsystem that we want
# to support a particular format, framesize and frameintervals
create_frame() {
    # Example usage:
    # create_frame <function name> <width> <height> <format> <name> <intervals>

    FUNCTION=$1
    WIDTH=$2
    HEIGHT=$3
    FORMAT=$4
    NAME=$5

    wdir=functions/$FUNCTION/streaming/$FORMAT/$NAME/${HEIGHT}p

    mkdir -p $wdir
    echo $WIDTH > $wdir/wWidth
    echo $HEIGHT > $wdir/wHeight
    echo $(( $WIDTH * $HEIGHT * 2 )) > $wdir/dwMaxVideoFrameBufferSize
    cat <<EOF > $wdir/dwFrameInterval
$6
EOF
}

# This function sets up the UVC gadget function in configfs and binds us
# to the UVC gadget driver.
create_uvc() {
    CONFIG=$1
    FUNCTION=$2

    echo "  Creating UVC gadget functionality : $FUNCTION"
    mkdir functions/$FUNCTION

    create_frame $FUNCTION 640 480 uncompressed u "333333
416667
500000
666666
1000000
1333333
2000000
"
    create_frame $FUNCTION 1280 720 uncompressed u "1000000
1333333
2000000
"
    create_frame $FUNCTION 1920 1080 uncompressed u "2000000"
    create_frame $FUNCTION 640 480 mjpeg m "333333
416667
500000
666666
1000000
1333333
2000000
"
    create_frame $FUNCTION 1280 720 mjpeg m "333333
416667
500000
666666
1000000
1333333
2000000
"
    create_frame $FUNCTION 1920 1080 mjpeg m "333333
416667
500000
666666
1000000
1333333
2000000
"

    mkdir functions/$FUNCTION/streaming/header/h
    cd functions/$FUNCTION/streaming/header/h
    ln -s ../../uncompressed/u
    ln -s ../../mjpeg/m
    cd ../../class/fs
    ln -s ../../header/h
    cd ../../class/hs
    ln -s ../../header/h
    cd ../../class/ss
    ln -s ../../header/h
    cd ../../../control
    mkdir header/h
    ln -s header/h class/fs
    ln -s header/h class/ss
    cd ../../../

    # This configures the USB endpoint to allow 3x 1024 byte packets per
    # microframe, which gives us the maximum speed for USB 2.0. Other
    # valid values are 1024 and 2048, but these will result in a lower
    # supportable framerate.
    echo 2048 > functions/$FUNCTION/streaming_maxpacket

    ln -s functions/$FUNCTION configs/c.1
}

# This loads the module responsible for allowing USB Gadgets to be
# configured through configfs, without which we can't connect to the
# UVC gadget kernel driver
echo "Loading composite module"
modprobe libcomposite

# This section configures the gadget through configfs. We need to
# create a bunch of files and directories that describe the USB
# device we want to pretend to be.

if
[ ! -d $GADGET/g1 ]; then
    echo "Detecting platform:"
    echo "  board : $BOARD"
    echo "  udc   : $UDC"

    echo "Creating the USB gadget"

    echo "Creating gadget directory g1"
    mkdir -p $GADGET/g1

    cd $GADGET/g1
    if
[ $? -ne 0 ]; then
        echo "Error creating usb gadget in configfs"
        exit 1;
    else
        echo "OK"
    fi

    echo "Setting Vendor and Product ID's"
    echo $VID > idVendor
    echo $PID > idProduct
    echo "OK"

    echo "Setting English strings"
    mkdir -p strings/0x409
    echo $SERIAL > strings/0x409/serialnumber
    echo $MANUF > strings/0x409/manufacturer
    echo $PRODUCT > strings/0x409/product
    echo "OK"

    echo "Creating Config"
    mkdir configs/c.1
    mkdir configs/c.1/strings/0x409

    echo "Creating functions..."

    create_uvc configs/c.1 uvc.0

    echo "OK"

    echo "Binding USB Device Controller"
    echo $UDC > UDC
    echo "OK"
fi

# Run uvc-gadget. The -c flag sets libcamera as a source, arg 0 selects
# the first available camera on the system. All cameras will be listed,
# you can re-run with -c n to select camera n or -c ID to select via
# the camera ID.
uvc-gadget -c 0 uvc.0

Why they didn't write a resolution that's bigger than 1920 x 1080 in the "uncompressed" and "mjpeg" lines ? I would like to use my HQ camera as its full potential.

I'm expecting to use my HQ camera as a webcam but with a full resolution, even if it's 4K/10fps.