flatpaks are designed for gui apps, and due to packaging dependencies, they are extra heavy in disk space. flatpaks are also most often installed on the user, not systemwide, so no root permissions needed to install.
apt installs systemwide exclusively, but can have a much smaller download size if the dependencies are already installed. Apps sharing dependencies means much less disk space. cli is supported.
they are extra heavy in disk space
While they use more disk space than most native packages, this point is often exaggerated. Flatpak uses deduplication and shared runtimes if multiple apps use the same runtime.
flatpaks are designed for gui apps, and due to packaging dependencies, they are extra heavy in disk space. flatpaks are also most often installed on the user, not systemwide, so no root permissions needed to install.
apt installs systemwide exclusively, but can have a much smaller download size if the dependencies are already installed. Apps sharing dependencies means much less disk space. cli is supported.
While they use more disk space than most native packages, this point is often exaggerated. Flatpak uses deduplication and shared runtimes if multiple apps use the same runtime.