I use an extension called "Bar Breaker" that hides these when you scroll away from the top/bottom of the page.[0] More people should know about it.
[0] https://addons.mozilla.org/en-US/firefox/addon/bar-breaker/
It would be better to have a single extension like uBlock origin to handle the browser compatibility, and then release the countermeasures through that. In fact, ublock already has "Annoyances" lists for things like cookie banners, but I don't think it includes the dick bar unfortunately.
Incidentally, these bars are always on sites where the navbar takes 10% vertical space, cookie banner (full width of course) takes another 30% at the bottom, their text is overspaced and oversized, the left/right margins are huge so the text is like 50% of the width... Don't these people ever look at their own site? With many of these, I'm so confused how anyone could look at it and say it's good to go.
— Joel Spolsky, What is the Work of Dogs in this Country? (2001): <https://www.joelonsoftware.com/2001/05/05/what-is-the-work-o...>
In my practice, I'll try a Jedi mind trick, e.g. "Trying to [state larger goal] makes a lot of sense. An even more effective way to do that is to [state alternate, non-toxic technique]."