Hacker News is not representative of the typical case. There are very few professional web developers who ignore Safari – a huge number of people surf on mobile

Hacker News is not representative of the typical case. There are very few professional web developers who ignore Safari – a huge number of people surf on mobile and a huge proportion of mobile users are Safari, so any developer ignoring them isn’t doing a very good job. All web developers have access to Safari – if they don’t use macOS then they use a tool like BrowserStack to test in Safari. This is a standard part of a web developer’s toolchain.