Another example: Flutter has 12k issues, but that's because it's the most popular cross-platform app framework. Also it's not all literally issues, it's just a tracking board for all kinds of "things" that need to be tracked.
(I work on Next) The issue count includes core issues, examples, and docs. We might consider breaking that out in the future. Next has ~1.2M active devs, so we expect a certain level of issues being opened weekly that will take time to investigate. With that being said, we definitely still want to get the total # down (and have many old issues that are stale and don't have repros we need to clean up)
Fantastic, it only has 2550 open bugs now! /s