>>539687068
https://argorar.github.io/WebMConverter/

drag your shitty clip into it, can leave everything default, then check "high quality mode" to get 2 pass vp9 encoding (best possible there is until moot invents vp10) and size limit to 3,95 and youre done

or you can do shareX and use region record, and have it output as webm. i do this when im lazy