Yes, you’re right! The report covers data from Instabug users only. We extracted data from 30K apps with a range of user base sizes, locales, devices, etc. I definitely agree with you, it’s not a definitive representation of the market, but we believe we have a good enough sample and that the findings are valuable for app developers.
We couldn’t find any other data on mobile bugs like this, so we decided to share what we have for the app dev community to have some benchmarks and insights.