I love live installers, I think the cinci one by reborn is one of the best it just downloads and install whatever you select.
The issue with that is you need an active high speed connection without a data cap which is an issue for some people. Also manjaro is a 3 or 4 min install where a live installer downloading everything is 30 mins.
AFAIK in case of universal iso either there is a default de/wm like xfce for endevour os which can be installed offline but to install other de/wm you need a stable network connection and you don’t want to install kde like that, do you
Its not cancelled just it doesn’t have a maintainer atm. The previous maintainer hasn’t the time to rewrite/update it and the team have asked for volunteers to maintain architect