I know someone who was a sole trader, had a serious car accident and couldn't work. They lived alone and between hospital appointments, physio and trying to manage day to day living after the accident, they didn't file a tax return on time that year. They had paid preliminary tax which was more than the amount due because of only working a few months that year. They filed the return late and had fines and interest charged by revenue which was paid. They thought that was it but then found their name was in the tax defaulters list online. Someone googled his business and the tax thing popped up with all the details, even his home address. He wasn't happy when his customer told him. It was about 12 years ago though, maybe its different since gdpr.
So its not just high tax arrears that are included, people with small fines too. Nobody bothered with it when it was in hard copy but very easy to access when its online.