I cannot agree more with Rene. Offering a large prize would work if only dedicated researchers are attracted. But we all know that wouldn't be the case.
To someone approaching the Voynich with no previous knowledge, the thing looks like it should be solvable. So we get a theory. Imagine that but a thousand times more than today. The study of the manuscript would become impossible. Imagine the ripple effects on other disciplines. People like art historians and paleographers would need to install a Voynich filter to keep their inbox workable.
Here's my view on the subject of this thread: the Voynich offers people the chance to wrestle with the Dunning–Kruger effect, "a cognitive bias in which people with limited competence in a particular domain overestimate their abilities." This has nothing to do with a person's overall intelligence, but rather their ability to understand that they have an awful lot to learn about the subject first.
Imagine someone who is not trained in coding accepting a job as a computer programmer. He knows his way around generative AI and manages to show some functional bits of code. He is on the "peak of mount stupid": he believes he can code, but actually he has none of the required skills, experience and competence.
In programming though, the required result is relatively concrete: I want the program to do "this". Our AI programmer will soon find out that he cannot deliver. Imagine the dread that overcomes him. He is now in the valley of despair. If he wants to get out, he has to stop his AI routines, learn coding (in a class or targeted self study) and then re-integrate AI into his workflow.
The Voynich leaves many people stranded on mount Stupid. But since this is a hobby, and not always as easy to assess as the performance of a computer program, nothing is driving them down to the valley of despair. So you get a whole mountain range, with on each peak someone yelling their theories at the others and getting upset that nobody joins them.
Luckily there are alternatives to this, and many people here on the forum and elsewhere appreciate having been in the valley and continuously climbing the slope out of it. But that requires a willingness to learn, to understand where criticism is coming from. To explore ways to apply scientific rigor to the study.
I don't really see the Voynich as something that actively destroys lives (I don't know of any examples myself, but I'm sure there are some). It's just one of the ways people can show their willingness to improve their critical thinking. If uncle Robert hadn't developed a crazy Voynich theory, maybe it would have been anti-vax rants instead. Or something about aliens. Or some conspiracy theory. The Voynich does not cause this, it is just one of the many paths to Mount Stupid.