Getting those stats seems practically impossible if you want to include as many languages as possible (I don't know how many TIOBE includes, they don't seem to state that anywhere on their site).
How do you measure the downloads on Github? Do you include only releases or also git clones? How do you compare languages with a package manager vs languages without one? What if the language compiler is hosted on a less popular git platform or maybe a personal website? Do you contact those regularly to give you the precise numbers? How do you know those numbers are reliable? How do you e.g. count the number of Rust toolchain installations without putting telemetry into rustup? Do you count nightly + stable + testing toolchains separately?
So it makes sense TIOBE only uses search results as those are comparable - or at least they seem to be, because search engines change their ranking and filtering methods over time and maybe personalize results.
How do you measure the downloads on Github? Do you include only releases or also git clones? How do you compare languages with a package manager vs languages without one? What if the language compiler is hosted on a less popular git platform or maybe a personal website? Do you contact those regularly to give you the precise numbers? How do you know those numbers are reliable? How do you e.g. count the number of Rust toolchain installations without putting telemetry into rustup? Do you count nightly + stable + testing toolchains separately?
So it makes sense TIOBE only uses search results as those are comparable - or at least they seem to be, because search engines change their ranking and filtering methods over time and maybe personalize results.