You seem to have constructed a strawman out of your very own interpretation of idealism. Idealism doesn't condemn the study of nature (i.e. science). It merely says that nature is "dreamt" and that consciousness is the primordial stuff and of a different category. Scientists generally have no problem with this, since they can go on studying observable nature as the purview of science, as it's intended.

The problem begins when some, emboldened by the successes of science with nature, don't heed the warning that studying consciousness with the intuition that it's also an emergent property of nature is a category error.

How has idealism been useful? It's prevented those who took the time to understand its arguments from wasting uncountable resources on non-starters, allowing to redirect those resources to something actually useful, whether in science or elsewhere. You seem to be of the notion that investing energies in an attempt to prove an intuition that can simply be reasoned as demonstrably false is justifiable. We'll agree to disagree.

30 years ago the philosopher David Chalmers, a materialist back then, had the particular distinction of articulating and cogently framing the idealist argument, better than any idealist had before, in what he coined The Hard Problem of Consciousness. Many scientists who set out to work on this problem thought that "hard" meant that it can be solved. What Chalmers really meant was impossible problem. For instance, in 1998 he entered in a friendly wager with Christof Koch, a scientist who was working on explaining how the brain gives rise to consciousness. David bet to Christof that 25 years in the future, Christof would have gone nowhere with his research. The bet expired last year, David won. In the meantime he himself had gone from a materialist to dabbling with panpsychism. He seems to currently be laying the foundation of his transition to idealism.

I've been watching Koch in recent years, as he engaged with Bernardo Kastrup. I could see that as recently as 2 years ago, Koch still really didn't grok the philosophy behind "the world as mind". Only a few months ago, after Kastrup had managed to help him solidify the pieces of that intuition, I heard him admit for the first time that consciousness cannot be material. He's now reframing his work with this intuition as part of his foundations. The stories of Donald Hoffman and Kastrup himself are similar. Computer scientists who set out to build conscious machines. They respectively got into cognitive science (Hoffman) and philosophy (Kastrup) to understand the nature of consciousness and ended up idealists.

Likewise in physics, there are some who still resist quantum nonlocality, which interprets local realism as false (material properties do not exist on their own, they require a "measurer" i.e. an experiencer, aka the moon doesn't exist when no one is looking). Quantum nonlocality was demonstrated experimentally and people won the Nobel prize for it (2022). Scientists who still cling to local realism, when it comes down to it, do so out of religiosity toward matter. They waste resources working on all kinds of increasingly less parsimonious theories, which clash with solidified conclusions from other fields of study.

I could go on, but I'll leave it at that. Good luck with the proof of consciousness via artificial brain.