I typically build on an old Debian distro. Put the binary in bin folder. Copy many of the libraries into the bin folder. I don't include glibc. Create a shell script that sets LD_LIBRARY_PATH and calls the bin executable. I also include .itch.toml file to allow it to run from the itch app easily.
Appimages are not working on clean installs of Ubuntu I've heard. Flatpak are a good solution but you can't easily have it download the runtime I believe unless you put it on flathub.