I find them really useful, I find youtube to be a good thing in moderation. But its very helpful to have a timer forcing me to thoughtfully use the time I've allocated.
The "UnTrap"-Add-On for Firefox can block the more detrimental aspects of youtube, like shorts or the recommendation of other videos.
I have it configured so that it always brings me directly to the "watch later"-playlist and I never go to the main page.
