Parce que la dernière version dans les dépôts est obsolète :

From an install script

To install the latest release from master, follow this simplified process.
First, you need to install the required packages:

# for Debian/Ubuntu
sudo apt install ffmpeg libsdl2-2.0-0 adb wget \
gcc git pkg-config meson ninja-build libsdl2-dev \
libavcodec-dev libavdevice-dev libavformat-dev libavutil-dev \
libswresample-dev libusb-1.0-0 libusb-1.0-0-dev

Then clone the repo and execute the installation script (source):

git clone https://github.com/Genymobile/scrcpy
cd scrcpy
./install_release.sh

When a new release is out, update the repo and reinstall:

git pull
./install_release.sh

To uninstall:

sudo ninja -Cbuild-auto uninstall