Why should I repay a loan?
While in CKII there was a opinion penalty towards the clergy, in CK3 I cannot find any downsides on having a loan.
The Wiki says that it "Removes all negative effects associated with holy order loans", but I couldn't find any such effect.
Is there some hidden effect I didn't notice nor encounter yet?
Solution 1:
If the loan is not repaid then the Holy Order will start making demands.
Usually they want one of your holdings, which will then no longer give you taxes nor levies.