Geopolymers have a lot of promise, as the linked article illustrates. The chief practical problem with them is once the hardener solution is added to the cement

Geopolymers have a lot of promise, as the linked article illustrates. The chief practical problem with them is once the hardener solution is added to the cement powder, setting is almost instantaneous. So there's no opportunity to work it like with Portland cement. And things like casting into forms can present problems like clogging material feeder tubes and incomplete filling of the forms. At least that was the situation the last time I examined geopolymer technology in depth a couple of decades ago. I did a quick read of the article and didn't see that issue addressed or any suggestion of progress.