It is possible to create opt-in, on-demand reporting tools.
Someone I know well created one such, based on a common reporting template of a major Free Software project, after realising that the template itself was based on information readily obtained from the system. Fleshing that out a bit resulted in an automatic syste self-documentation tool. They'd introduced it to the support group at one former company, and informal feedback several years later was that this was the principle diagnostic utility for the team. There was no ongoing telemetry, merely a "here's the script, run it and send us the output". (If necessary, the output could have been automatically emailed or transmitted by other means.)
There are now several of these, the "About This Mac" utility on OSX, as well as several for Linux, of which I'm aware.
No, they're not app-specific diagnostics, but precisely the same principles apply.
Someone I know well created one such, based on a common reporting template of a major Free Software project, after realising that the template itself was based on information readily obtained from the system. Fleshing that out a bit resulted in an automatic syste self-documentation tool. They'd introduced it to the support group at one former company, and informal feedback several years later was that this was the principle diagnostic utility for the team. There was no ongoing telemetry, merely a "here's the script, run it and send us the output". (If necessary, the output could have been automatically emailed or transmitted by other means.)
There are now several of these, the "About This Mac" utility on OSX, as well as several for Linux, of which I'm aware.
No, they're not app-specific diagnostics, but precisely the same principles apply.