Pinch-to-zoom via touchpad or touchscreen is disabled by default in Microsoft Edge on Ubuntu Linux. The fix requires launching Edge with two flags: --enable-features=UseOzonePlatform and --ozone-platform=wayland. To avoid running Edge from the command line each time, you can edit the launch script at /opt/microsoft/msedge/microsoft-edge (requires root) to append these arguments. Be aware that Edge updates will overwrite this change, requiring you to reapply it.
