At my previous employer, I had to convince several people in my team that wearing a suit was NOT a reason to reject a candidate out of hand. It's really difficult to gauge the expected dress code at a company beforehand, but it's not good advice to just blindly dress up.
Perhaps the suit wasn't the one level up that people are talking about? If you accidentally go 3 levels too formal, you've definitely ruined the initial impression.
Me personally, I like working at places where people can wear shorts and flip-flops. One level up is "pants and shoes, with socks", not even a collared shirt. Maybe a single-color new T-shirt, to be safe. A full suit would be an alarmingly bad read of the culture, and at that point we'd have made you come eat lunch at a burrito place to get a read on whether you're really a bad fit or just socially awkward.
The best thing I heard from an interviewee that was wearing a suit was that they interviewed elsewhere nearby that morning, and those people needed to be impressed with clothing.
At my previous employer, I had to convince several people in my team that wearing a suit was NOT a reason to reject a candidate out of hand. It's really difficult to gauge the expected dress code at a company beforehand, but it's not good advice to just blindly dress up.