There are graduating seniors in high-school this year. That group of unregistered voters needs to be coaxed to register, and vote. They need easy, step by step directions. They need to understand their new power of citizenship. They can be tried as adults. They should know who the sheriff is. They should know its an elected position. They need to learn this shit, and most likely it's not gonna happen in school. Please ticktock or whatever. Make it viral.
I live in a country where everybody who is entitled to vote, gets a vote in their mail box and a dedicated place where they can go and vote. They can even send in their votes before hand or vote in the local library.
I don't see how one side or the other or any can benefit by low voting percentages
Republicans are currently making it harder for left-leaning populations to vote, by closing polling stations in urban areas or opposing vote-by-mail. Automatic voter registration is being actively resisted. That is "why".
Voter registration became a thing in the 1800s to limit the voice of immigrants, adopted state by state.
Oregon first, and about a dozen other states since, have made registration automatic when you get a driver's license or state ID.
Central registered of all citizens with ID-number. I'm pretty sure your nation has it, as does mine.
So the government knows where you live, and where you can vote. If you move these things are automatically updated. So it's easy to make sure everyone can vote in the "correct" ballots ect.