Is it them or is it me?
With everyday apps the first question is whether the problem is on your side. A declared incident answers it at once. When nothing is declared, the next step is to look at the component list: voice servers by region for Discord, products by region for Zoom, sync versus website for Dropbox. Problems in one component leave the rest working.
These companies differ a lot in how much they declare. Some publish several incidents a month with detailed updates; others publish a handful per year. The 90-day strip on each row gives a sense of that habit, and it is the reason this site writes "no incident reported" instead of "working".