But that would just increase the number of issues reported over time. It can't scale. When should they stop supporting these devices? If their telemetry shows 1 user on an iPad from 5 years ago, does that mean they need to support it? What about 1 user on an iPad from 50 years ago? Again, where does it end? You shouldn't be running an out of date browser at all, that's a major security risk.
Support doesn't need to be perfect. An out-of-date browser should be security-OK for things that don't involve money. Maybe JS needs to get switched off. So sites should work without JS.