Apart from NPM, Webpack is still the king of build tools. This is no doubt due to the rise of no-config Webpack wrappers like Create-React-App and Next.js.
This could prove itself a double-edged sword though: if a better alternative ever comes along, these libraries might end up switching to it without a second thought.
Per-library survey results.
Number of Libraries Used
How many different libraries are developers using (defined as respondents who picked “have used before and would use again”)?
On a scale of one to five, how happy are developers with the current state of Build Tools tools?