It may be hard to remember now that we’ve had frequently-updated browsers for so long but not everyone updated promptly. That lead to a lot of now-vestigial frontend culture where developers would build around the oldest browser they couldn’t afford not to support.
That colored a lot of low-level decisions about how events were implemented, false claims about virtual DOMs being fast or efficient, and especially the culture of adding dependencies because you need a feature which wasn’t in Internet Explorer. Once that trend is established, it’s hard to change without breaking compatibility and so you end up with people in 2025 using slower code based on the support matrix set over a decade earlier.
(And to be clear, I’m not saying that React has no redeeming values - only just it’s healthy to reconsider decisions made in previous decades to see whether the cost/benefit ratio has changed. I think we’re going to see some really interesting shifts as funding for open source shifts in a non-boom economy, but also as LLMs adjust the working style & relationship many people have to maintenance.)
That said, I was on a team that was still supporting IE6 around 2014. We had clients, mostly in China from what I heard, that were required to use it because internal tooling had developed around it and their IT teams wouldn't let them upgrade.
Yeah, I worked on things geared towards the general public so we had to support, say, a senior citizen who was using old computers at the underfunded library or senior center. They weren’t a high percentage of total traffic but it was still millions of people.
It was definitely frustrating knowing that a better world was possible but not quite there.
If you are in the US, it's more likely than not that your local/state court system is managed by software that runs almost entirely on VBScript within an IE7 wrapper.
Last release of IE6: 2008
Concerted campaign to make everybody stop using IE6: 2009
Microsoft joins that campaign: 2011
First release of React: 2013