With all DEs being listed as requiring 2 or 4 GB of RAM, there is quite a lot of ambiguity in that column.
Which distro(s) were the RAM requirements tested in? Do the amounts refer to the amount of RAM the DE processes use, or to what the entire distros use? On what page/test did it say that e.g. LXQT require 2 GB of RAM?
My research do indicate that some of the amounts roughly correspond to the requirements of various major Ubuntu 21.4 forks (e.g. Lubuntu), but this doesn't seem like it's dealing a fair hand to more compact (though admittedly much less gaming-oriented) distros who perhaps only need 1 GB RAM for the whole distros.