good idea/bad idea, necessary democratic reform or authoritarian imposition? are there better or worse ways to do it?
No, it’s not. Forcing someone who is not knowledgeable or interested to vote is in no way the same as testing whether someone is educated to determine if they should be allowed to.
Cousin cleatus can show up and write fuck you on their ballot and put it in the box if they are not knowledgeable or interested in voting. Or they can vote for the things which matter to them, because they are a member of society and should not be deprived of their right to a voice in the government which rules them as well.
I’m going to try one more time here…
Nobody said ‘deny’ at any point in this exchange. The OP said mandatory/compulsory, aka force them to do so.
Deny and compel are NOT the same thing, they are in fact functionally the opposite each other.
What point is there to compel someone who self-selects as lacking in knowledge/interest in the process. You waste time and resources for the voter, the process administrators, enforcement personnel, everyone any anyone involved including the willing and eager participants by creating longer lines and a wasting their tax funds just to satisfy a mandate by having Cleatus write ‘fuck you’ on a ballot.
If that is too complicated to understand I can’t help you.
by creating longer lines and a wasting their tax funds
This assumes the voting process will stay exactly the same as it is today
Of note - mandatory only means that it is legally required. It does not mean you have to force them to show up. It specifies nothing in terms of actual implementation, other than a law requiring a vote.