IEEE's methodology[2] is sensible given what's possible, but the data sources are all flawed in some ways (that don't necessarily cancel each other out). The number of search results reported by Google is the most volatile indirect proxy signal. Search results include everything mentioning the query, without promising it being a fair representation of 2025. People using a language rarely refer to it literally as the "X programming language", and it's a stretch to count all publicity as a "top language" publicity.
TIOBE uses this method too, and has the audacity to display it as a popularity with two decimal places, but their historical data shows that the "popularity" of C has dropped by half over two years, and then doubled next year. Meanwhile, C didn't budge at all. This method has a +/- 50% error margin.
[1]: https://redmonk.com/rstephens/2023/12/14/language-rankings-u... [2]: https://spectrum.ieee.org/top-programming-languages-methodol...