I've switched to watching youtube videos using mpv. yt-dlp thankfully works, and this way, I can watch the video any way I want.

I’m already a Premium user, so I suspect I won’t see a change. That said, I’m against turning formerly free features into paid ones. Especially something as useful as playback speed, which has been around forever. Whoever is making the decisions at YouTube is seems to be making one bad decision after another.

The biggest issue with going to an alternative is that one doesn’t really exist. Yes, there are other video sharing sites, but they have a tiny sliver of the content YouTube has, as a viewer. As a creator, they have only a tiny sliver of the viewers, which hurts monetization efforts.

Does this bookmarklet work to give you 2x speed anyway?

    javascript:for(v of document.getElementsByTagName('video'))v.playbackRate=2;void(0)

Product management at YouTube baffles me.

What is being improved by removing speed controls? Certainly nothing on the user side of the equation.

No worries. The speed is built into the web browser. YouTube cannot disable it. Meaning, even if they remove the option from the player UI, the functionality cannot be removed. A simple browser extension will therefore always be available to supplement it.