You aren't seeing the things from the POV of the rulers of that place. Which is why that benefit makes no sense. Remember that the ruling system there is a monarchy.
No it does, and if you want me to think from the perspective of the monarchy it makes more sense.
The exemption to guild quests likely does not apply to royal orders, which would come from outside the guild, so from a ruler's perspective it means the strongest problem solvers are not as likely to be wasting time on some other nobles issues when they are needed, and the royals just need to make sure the compensation is good enough and most will accept unless is is a suicide mission.
That is if they even care about Adventurers since they have forces like their knight orders.
As well Monarchs need the strongest people to be loyal to them and not someone else. The forced quests is a good way to build resentment from the people you need loyal, or for a noble plotting to take more power to build a relationship with an adventurer by giving easier nominated quests so the adventurer so the Adventurer can ignore other quests from either lesser nobles or even open ones that they need done.
Also in the worst case the benefit makes striving for the rank enough of a motivation to get people to do so, and it would be trivial for a monarch to still have most adventurers assassinated if they were a real problem, and the higher ranks are likely little more than a ranked list of potential threats, so you want them at the rank that coincides with their threat level.
