Snap Packages are created separately from a software's release and they may not be made by the software's developer. Each time some software is updated the snap package must also be updated so people can get the latest version of the software through Snap. You can see on the SnapCrafter's website that there has not been an update to the Arduino IDE snap since December 2022, which is why when you installed the Snap you got an outdated version of the software. You won't be able to get the Arduino IDE at the latest version with Snap until the owner of this Snap Package updates it. This happens with most package managers. They make installation easier and in the case of APT they will be tested for your release of Ubuntu; but typically to get the latest version of any software you have to go directly to their website and use only the official packages offered.
Regarding where to put software can be argued for hours, but I would recommend putting the files in /opt and creating a symlink to /usr/bin. Do the following.
Uninstall the Snap sudo snap remove arduino
Create the directory in /opt
sudo mkdir -p /opt/arduino-ide
Copy the unzipped contents into there:
sudo cp -r ~/Downloads/arduino-ide_nightly-20231006_Linux_64bit/* /opt/arduino-ide/
Create a symlink of the binary into /usr/bin. Doing this means the Arduino binary will be available to run from the terminal without referencing the entire file-path, i.e. you can run arduino-ide to open it.
sudo ln -s /opt/arduino-ide/arduino-ide /usr/bin/
Finally, in order to get a nice launcher-tile in the applications tray, we have to create a .desktop file and place it in ~/.local/share/applications/
Create the file and open it with a text editor:
gedit ~/.local/share/applications/arduino-ide.desktop
Paste in the following:
[Desktop Entry]
Name=Arduino IDE
Exec=/opt/arduino-ide/arduino-ide
Terminal=false
Type=Application
Icon=/opt/arduino-ide/arduino.png
Comment=Arduino IDE
Categories=Development;
Save and close the file.
3. Download the icon and save it in /opt:
sudo wget https://raw.githubusercontent.com/arduino/arduino-ide/main/electron-app/resources/icons/512x512.png -O /opt/arduino-ide/arduino.png
I would have phrased it differently: "if all users of the computer will use the application, put it in /opt (or maybe /usr/local), even if that is only one user. If no one but you will use it, even if your computer somehow acquires additional users, put it in ~/bin"