Sure, a few years ago the difference between browsers was really quite large. But we're in 2017 and most of the most used browsers are mostly in line with the supported features and expected behaviour of them.

But... safari is now the one that has weird behaviour that does not occur in Firefox, chrome and edge. Just because historically there was a massive split in behaviour doesn't mean that Safari gets off free. It's the one browser I hate testing because there are usually edge case and unexpected behaviour.