If you skim the positions and get an 80% hit rate on policies which actually match yours (which means you screw it up and guess wrong 20% of the time) that is still way better than not participating at all.

This takes a toooooon more time than looking up people once you have a ballot. But I'm the other hand, voting isn't such a huge thing for controlling local political outcomes.

The local officials have a similar lack of information about what voters want. So they tend to be easily influenced by a small number of highly motivated people that show up to meetings. In a town or 50,000, if 100 people show up to a meeting and there's no significant opposition, it's quite likely that the 100 people will win, even if they don't represent the community. Because with the small amount of effort that it took to get 100 people to show to a meeting will go much further come election time, and that 100 people who bothered to show up will remember a vote that went against them when they were the only people that showed up for public input.

IMHO, this is hugely un democratic, and a source of many problems. But it's how politics work: connections and organizing, instead of a poll of everybody's opinion on every issue.