I don't know what is happening here. I get on youtube every single day and I have Firefox with uBlock and NoScript, as I had them since ~2018 when I moved off Chrome. There is absolutely no delay for me at all. No change in any delay, same today as it was a week before or the weeks before that. Also I'm an uBlock user since times immemorial, on Chrome before Firefox too, so I never saw any ads. The only time I see ads are when my clients share their screen and trust me, I install uBlock instantly in their browser.