The right to remain silent is not necessarily a blessing to a defendant. Because having a choice is not necessarily a good thing. Unless the decision to testify is uncorrelated with guilt, that decision by itself will convey information to the jury. (I know juries are instructed not to infer anything. But that is impossible.) So for example, if those who take the fifth are more likely to be guility (as I would guess. Are there data on this?), then an innocent person’s “right” to remain silent is actually a right to partially incriminate himself
A prohibition against defendants testifying on their own behalf is worth considering. If the goal is to protect defendants from incriminating themselves, then the above benefit offsets the obvious cost.
And if that is too extreme there are middle grounds to consider. For example, since the defense puts on its case last, the defendant does not make his decision until after the prosecution has introduced evidence. A defendant might want to commit in advance of that evidence being revealed that he will not testify so that nothing can be revealed by his decision being contingent on the evidence. As far as I know this commitment is not possible under current law.
In general the earlier you commit not to testify the less can be inferred from this. So we should allow citizens to register their commitments before they are charged with any crime. When you register to vote you also check a box that says whether you or not you will testify in the event you are ever charged with a crime.