Japan has an incredibly high convicted rate.

this is not a good thing.

I don't know about the historical reasons. But I do think it is good to have some ordinary people influencing the judgement as well, rather than just some judge sitting in their ivory tower.

countries that inherited the English common law. Personally I think the French system is better but here we are.

It's not Western countries, it's countries that inherited English common law UK, US, etc). France for example doesn't have juries iirc. The judges act more as investigators than as referees.

I personally think it's better to have 12 people deliberating over the evidence etc and formulating reasons for their conviction than one

in the US, some people never get a juror summons, while others get it every year, if not more than once. and they often use recent DMV renewal/registration , and recently voting as primary source of jurors. many jurors cant AFFORD to have time off for being on jury duty at all.

better to have a pool of willing jurors(who wants to be on jury duty every year) that they can rotate around, so as to not invite biases.

Jury duty exists because of the jury trial.

The use of the jury trial exists as a counter to the state potentially obtaining control of the courts and using it to impose criminal legal penalties on those it dislikes. You'll notice that Donald Trump has had investigations against and can have charges issued againat a lot of people that he doesn't like. But a prosecutor then has to be able to successfully make their case to a jury. Not much action on that front.

Some "want to avoid" scenarios include the legal system under the Nazis:

https://en.wikipedia.org/wiki/Law_of_Nazi_Germany

From 1933 to 1945, the Nazi regime ruled Germany and, at times, controlled most of Europe. During this time, Nazi Germany shifted from the post-World War I society which characterized the Weimar Republic and introduced an ideology of "biological racism" into the country's legal and justicial systems.[1] The shift from the traditional legal system (the "normative state") to the Nazis' ideological mission (the "prerogative state")[1] enabled many of the subsequent acts of the Hitler regime (including its atrocities) to be performed legally. For this to succeed, the normative judicial system needed to be reworked; judges, lawyers and other civil servants acclimatized themselves to the new Nazi laws and personnel. As of 2021, a few laws from the Nazi era still remain codified in German law.[2][3][4][5]

Or the Star Chamber:

https://en.wikipedia.org/wiki/Star_Chamber

That whole "... of your peers" thing. Supposedly, it's harder to influence and corrupt 12 jurors than it is a single judge.

I have seen cases where the judge reversed the juror's decision, although I think that's really rare.

I would personally rather put my fate in the hands of 12 ostensibly average people than one judge.

It's a historical quirk. When the Anglo-Saxons invaded Britain and set up a new government, there was one King, and there was one King's court. As in, all court happened in the King's court. The King would travel to various areas of the country to hold Court. However, as the government and legal system grew, the number of cases outgrew the King's ability to hear them all. He couldn't be in so many places at once.

So, juries were a pragmatic solution. For minor issues, the locals in question were charged to handle their own affairs on the King's behalf. However, for major controversies and felonies, they had to travel to the King's Court.

Over time, the jury system became an established part of the culture. A judge can be biased or corrupted unfairly, but it's the will of the people to only deliver just punishment.