On top od that it takes more vertical space so more % of the video is covered by controls that are not that transparent so the whole control block is covering it in full comparing to previous where only the actual icons and text did cover the video with the gradient to help make it visible if video is the same color.
But one way or another I avoid yt so it doesnt really affect me.
My guess it is zip'ping the directory in memory to send it as single zip file, hence use a lot of memory. Better to zip/tar directory yourself and send that file over.