I mean, I've had iOS crash while using safari more often than I had windows 98 crash while using IE.
At least back in the IE days, when a user found a site they couldn't open in IE, they could go download firefox.
When a user encounters a websites that doesn't work on iOS safari, they can't download a different browser.
Even worse, when you report the bug to the site owner (say your friend), they'll then say "Oh, sorry, I don't own an iPhone or macbook, so I'd have to pay $800+ to reproduce your bug", while with IE, it ran on basically any computer, and I think windows back then still had a trial version you could use for free.
And with Safari, I can’t test any specific issues because we only have one mac, and it’s old and can’t run a current Safari. The situation is slightly better than with IE, as multiple macOS versions apparently (or so I was told) can run a newer Safari, but still not all.