In Bookworm, the old, divine mandated way of succeeding the 'king' position is through selection among candidates who have passed the tests from the Gods and were given a magic tool that essentially run 'countrymanagement.exe' (also act as magical google)
Then one queen wanted her incompetent son to succeed her, and made a lesser version of said magic tool, which still have the countrymanagement.exe so the son can still run the country fine.
Then the son passed it on to his children, and repeat.
Eventually nobody go through the trials because passing down the tool was considered to be the expected way and you might be seen as trying to usurp the throne for getting one yourself.
The religion declined, but because worshipping the Gods is how you get their blessings people get less blessings over time and thus are weaker in overall magic power. (another thing Myne accidentally get plenty of due to her time in the temple and her high magic power offerings)
But then when the tool was lost in a coup, shit hit the fan because at this point everyone is so used to 'handing down the tool' being the tradition that nobody in the country is aware of the old and true method of doing it.
In fact when Myne accidentally start herself on that path (she just want to get into the secret library supposedly only royals can get into...) they accused her of trying to usurp the throne (though partly due to her teacher's hidden royal lineage and they think he's using her to get it)