The Linux Experiment recently looked into touchscreen support of different desktop enviromenents. His findings mostly align with your comment. However, this seems to be one of the rare cases where the distro matters for Gnome. Upstream Gnome (e.g., as shipped by Fedora) works fine with touch screens, but support on Ubuntu Gnome appears to be quite broken.
The Linux Experiment recently looked into touchscreen support of different desktop enviromenents. His findings mostly align with your comment. However, this seems to be one of the rare cases where the distro matters for Gnome. Upstream Gnome (e.g., as shipped by Fedora) works fine with touch screens, but support on Ubuntu Gnome appears to be quite broken.
The Linux Experiment videos: