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.
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.