Is Youtube still using Polymer 1.0 with the deprecated shadow DOM v0 that's only supported in Chrome without polyfills [0]? I still use the old version because

Is Youtube still using Polymer 1.0 with the deprecated shadow DOM v0 that's only supported in Chrome without polyfills [0]? I still use the old version because the new version was annoyingly slow in Firefox last time I checked, and I have no reason to switch to the newer one with lower information density and contrast. [0] https://www.theverge.com/2018/7/25/17611444/how-to-speed-up-youtube-microsoft-edge-safari-firefox https://www.theverge.com/2018/7/25/17611444/how-to-speed-up-...