Random selection is necessary to create stable meritocratic institutions

> Juries, widely trusted to impartially deliver justice, are the most familiar instance.

Trusted by those that have not looked into whether this is actually the case. The first prime minister of Singapore, Lee Kuan Yew, was famously against trial by jury, because of how easily lawyers can abuse biases in multiracial societies, based on his first-hand experience [1].

A UK study found his experience is the norm, not the exception - Black and minority ethnic (BME) jurors vote guilty 73% of the time against White defendants, but only 24% of the time against BME defendants [2]. (White jurors vote 39% and 32% for convicting White and BME defendants, respectively. You read that correctly - Whites are also biased against other Whites, but to a much lesser degree)

Edit: To answer what is the alternative to juries: Not all countries use juries, in some the decision is up to the judge, and in some, like France, they use a mixed system of judges and jurors on a panel [3]. The French system would be my personal preference, with the classic jury system coming in second, despite my jury-critical post. Like democracy, it's perhaps the least bad system that we have, but we shouldn't be under any illusions about how impartial and perceptive a group of 12 people selected at random is.

[1] https://postcolonialweb.org/singapore/government/leekuanyew/...

[2] https://www.ucl.ac.uk/judicial-institute/sites/judicial-inst... - page 165 (182 by pdf reader numbering), figure 6.4

[3] https://en.wikipedia.org/wiki/Jury

And what is the other option? Just led the judge alone decide?

Yes I trust judges more than I trust juries.

And it usually isn't a single judge. There is a panel of judges or en banc.

And juries aren't universal either. Lots of other countries don't have juries but they have a fair and equitable justice system. Look up civil law vs common law.

I want the judge to keep the lawyers in check so they cannot. Judges are trustable because the jury limits their power. If I am a lawyer I know whothe judges are and it is to my advantage to figure out their bias (including judge shopping if there is more than one in the area), looking for embaressing things or blackmail material, what bribes they will accept (often in form of donation to a family charity) and so one.

which is to say the reason I trust judges is the jury keeps them in check by ensuring there isn't value in the above corruption.