I recall in the elections of 1994 that I was in a voting center (a school) and two things did not let my mind since then regarding the voting system back in the day: (1) candidates representatives arriving with buses and more buses of people that received money to vote in someone (in those days with a BRL strong like USD) and (2) During the votes counting endless amount of ballots being trashed way due to people writing silly things or some other reasons.

My mother used to sell things to people during the entire election day, and when we went to discard part of the trash in the school we could see ballots on the thrash.

On top of that, in some places we had complete network of fraudsters responsible for ballot register (Guia/Boletim de Urna in PT-BR) and counting (apuração in PT-BR) that some voting sections did not had blank/null (voto em branco/nulo in PT-BR) plus had sometimes 3x the original amount of people in the final counting.

I said that because even if the system is not perfect today, would be a bad decision to go back to that system.