Debian favors stability over anything else so the packages are thoroughly tested before release and then only upgraded for security issues, until the next release 2 years later when everything gets an update.
Ubuntu favors releasing more recent package versions constantly throughout the period between major releases.
You can install packages on Debian from the backports repo if you occasionally need an package to be a more recent version.
Another option is to install apps from Flatpak. The apps in Flatpak have their own separate dependency system and can be used on any distro.
If neither of these works for you and you find yourself constantly wishing packages were newer you may want to consider a different distro.
Some people switch their Debian from stable to testing to get similar updates to Ubuntu. You can try that but please understand you may experience the occasional issues.
Be wary of adding external repos (that don’t point to debian. org) because they can mess with the package dependencies and prevent you from upgrading to the next version when it comes out. (This also applies to Ubuntu.)