This was asked and closed but the answer seems a bit off. After all, it is possible to run rattle inside a docker container kayon/rattle admittedly, performance where the Xserver is physically distant from the rattle server is apt to be worse, it certainly is possible to run X apps remotely.
It would be a kindness to include the (admittedly obsolete) RGtk2 (and its dependencies) in RStudio cloud's environment.