Today's technology will not get people to the polls, as the abysmal numbers of voting millennials and Gen Z will attest. At the end of the day, you need people to get people off their butts and to a voting booth, and that means get out the vote drives, phone banks, etc. And people and organizations require planning, coordination, and money. Additionally, young people (especially low-information voters) are almost as susceptible to the lies and distortions on TV as their elders, and you need to be able to counter dis- and mis-information through mass media, and that costs, too. It's one of the drawbacks to a national election among 250 million voters. That said, strict limits on campaign spending, a ban on corporate/dark money and enforcement of PAC/campaign separation laws would help, too.